diff --git a/exam156/generate.php b/exam156/generate.php
new file mode 100644
index 0000000..2019d93
--- /dev/null
+++ b/exam156/generate.php
@@ -0,0 +1,37 @@
+<?php
+header('Content-type: image/jpeg');
+
+$mysql_host = 'localhost';
+$mysql_user = 'example_user';
+$mysql_pass = 'Kolosnjaj4321!';
+$mysql_db = 'example_database';
+$con = mysqli_connect($mysql_host, $mysql_user, $mysql_pass);
+mysqli_select_db($con, $mysql_db);
+
+if (isset($_GET['id'])) {
+    $id = $_GET['id'];
+
+    $query = mysqli_query($con, "SELECT `email` FROM `users` WHERE `id` ='" . mysqli_real_escape_string($con, $id) . "'");
+    if (mysqli_num_rows($query) >= 1) {
+        $query_result = mysqli_fetch_assoc($query);
+        $email = $query_result['email'];
+    } else {
+        $email = 'ID not found';
+    }
+} else {
+    $email = 'No id specified.';
+}
+$email_length = strlen($email);
+
+$font_size = 4;
+
+$image_height = imagefontheight($font_size);
+$image_width = imagefontwidth($font_size) * $email_length;
+
+$image = imagecreate($image_width, $image_height); // Stvaranje prazne slike
+
+imagecolorallocate($image, 255, 255, 255); // boja pozadine podesena na belo
+$font_color = imagecolorallocate($image, 0, 0, 0); // boja fonta podesena na belo
+
+imagestring($image, $font_size, 0, 0, $email, $font_color);
+imagejpeg($image);
diff --git a/exam156/index.php b/exam156/index.php
new file mode 100644
index 0000000..1b200e7
--- /dev/null
+++ b/exam156/index.php
@@ -0,0 +1,4 @@
+Name:<br>
+Alex <br><br>
+Email:<br>
+<img src="generate.php?id=2">
\ No newline at end of file
diff --git a/exam161/generate.php b/exam161/generate.php
new file mode 100755
index 0000000..79b56bf
--- /dev/null
+++ b/exam161/generate.php
@@ -0,0 +1,29 @@
+<?php 
+
+header('Content-type: image/jpeg');
+
+if(isset($_GET['source'])){
+    $source = $_GET['source'];
+
+    $watermark = imagecreatefrompng('php.png');
+
+    $watermark_height = imagesx($watermark);
+    $watermark_width = imagesy($watermark); // imagesx uzima sirinu ucitane slike
+
+    // Ova funkcija stvara praznu sliku s određenom širinom i visinom, koristeći prave boje umesto indeksiranih 
+    $image = imagecreatetruecolor($watermark_width, $watermark_height); 
+    $image = imagecreatefromjpeg($source);  
+
+    $image_size = getimagesize($source); 
+    $x = $image_size[0] - $watermark_width - 10;
+    $y = $image_size[1] - $watermark_height - 10;
+
+    imagecopymerge($image,$watermark,$x,$y, 0, 0,$watermark_width,$watermark_height, 40);
+    imagejpeg($image); // ili imagejpeg($image, $source.'.watermark.jp'); sto nam pravi sliku u folderu ako stavimo drugi parametar
+     
+    
+} else {
+    echo 'No source suplied';
+}
+
+?>
\ No newline at end of file
diff --git a/exam161/index.php b/exam161/index.php
new file mode 100755
index 0000000..9b90129
--- /dev/null
+++ b/exam161/index.php
@@ -0,0 +1 @@
+<img src="generate.php?source=phone2.jpg" />
\ No newline at end of file
diff --git a/exam161/phone2.jpg b/exam161/phone2.jpg
new file mode 100755
index 0000000..65076a5
Binary files /dev/null and b/exam161/phone2.jpg differ
diff --git a/exam161/phone2.jpg.watermark.jpg b/exam161/phone2.jpg.watermark.jpg
new file mode 100644
index 0000000..8dc6c0f
Binary files /dev/null and b/exam161/phone2.jpg.watermark.jpg differ
diff --git a/exam161/php.png b/exam161/php.png
new file mode 100644
index 0000000..e99e319
Binary files /dev/null and b/exam161/php.png differ
diff --git a/exam164/HappySwirly-KVB7l.ttf b/exam164/HappySwirly-KVB7l.ttf
new file mode 100644
index 0000000..c315bc9
Binary files /dev/null and b/exam164/HappySwirly-KVB7l.ttf differ
diff --git a/exam164/generate.php b/exam164/generate.php
new file mode 100755
index 0000000..3e7ee2d
--- /dev/null
+++ b/exam164/generate.php
@@ -0,0 +1,31 @@
+<?php 
+session_start();
+
+header('Content-type: image/jpeg');
+
+$text = $_SESSION['secure'];
+$font_size = 30;
+
+$image_width = 120;
+$image_height = 40;
+
+$image = imagecreate($image_width,$image_height);
+imagecolorallocate($image, 255, 255, 255); 
+$text_color = imagecolorallocate($image, 0, 0, 0);
+
+for ($x = 1; $x <= 30; $x++) {
+    $x1 = rand(1,100);
+    $y1 = rand(1,100);
+    $x2 = rand(1,100);
+    $y2 = rand(1,100);
+    
+    imageline($image,$x1,$y1,$x2,$y2,$text_color);
+}
+
+
+$font_filename = '/var/www/nikola/practice/exam164/HappySwirly-KVB7l.ttf'; // mora cela putanja 
+
+imagettftext($image, $font_size, 0, 15, 30,$text_color,$font_filename,$text);
+imagejpeg($image);
+
+?> 
\ No newline at end of file
diff --git a/exam164/index.php b/exam164/index.php
new file mode 100755
index 0000000..e8bb7b7
--- /dev/null
+++ b/exam164/index.php
@@ -0,0 +1,27 @@
+<?php 
+session_start();
+
+
+if(!isset($_POST['secure'])){
+    $_SESSION['secure'] = rand(1000, 9999);
+}else {
+    if($_POST['secure'] == $_SESSION['secure']){
+        echo 'You are not robot';   
+    } else {
+        echo 'Try again';
+        $_SESSION['secure'] = rand(1000, 9999);
+    }
+}
+   
+
+
+
+?>
+<br>
+<img src="generate.php"/><br>
+
+<form action="index.php" method="POST">
+    Write a number from picture:
+    <input type="text" size="6"name="secure">
+    <input type="submit" value="Submit">
+</form>
\ No newline at end of file
diff --git a/exam168/index.php b/exam168/index.php
new file mode 100644
index 0000000..851a2c8
--- /dev/null
+++ b/exam168/index.php
@@ -0,0 +1,25 @@
+<?php
+header('Content-type: image/jpeg');
+
+if(isset($_GET['image'])){
+    $image = $_GET['image'];
+
+    $image_size = getimagesize($image);
+    $image_width = $image_size[0];
+    $image_height = $image_size[1];
+
+    $new_size = ($image_width + $image_height) / ($image_width * ($image_height / 45));
+    $new_width = $image_width * $new_size;
+    $new_height = $image_height * $new_size;
+
+    $new_image = imagecreatetruecolor($new_width, $new_height);
+
+    $old_image = imagecreatefromjpeg($image);
+
+    imagecopyresized($new_image,$old_image,0,0,0,0,$new_width,$new_height,$image_width,$image_height);
+    imagejpeg($new_image);
+
+}
+
+
+?>
diff --git a/exam168/phone2.jpg b/exam168/phone2.jpg
new file mode 100755
index 0000000..65076a5
Binary files /dev/null and b/exam168/phone2.jpg differ
diff --git a/exam172/include.inc.php b/exam172/include.inc.php
new file mode 100644
index 0000000..05a682b
--- /dev/null
+++ b/exam172/include.inc.php
@@ -0,0 +1 @@
+Hello!
\ No newline at end of file
diff --git a/exam172/index.php b/exam172/index.php
new file mode 100644
index 0000000..2274b9b
--- /dev/null
+++ b/exam172/index.php
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+
+<script type="text/javascript">
+
+//AJAX code
+function load(thediv, thefile){
+
+    //Ovde proveravamo da li browser podrzava objekat XMLHttpRequest, ako podrzava pravimo nov objekat, ako ne podrzava
+    //tada se koristi alternativni pristup stvaranju objekta kroz ActiveXObject.
+
+    if (window.XMLHttpRequest){
+        xml_http = new XMLHttpRequest();
+    } else {
+        xml_http = new ActiveXObject('Microsoft.XMLHTTP');
+    }
+
+    //kada se stanje objekta xml_http promeni funk ce se aktivirati
+    //funkcija proverava da li je stanje objekta dostiglo readyState=4 sto znaci da je zahtev zavrsen
+    //i da li je status HTTP odgovora 200 = 'OK'
+    //responseText ili odgovor se postavlja kao html sadrzaj
+
+    xml_http.onreadystatechange = function() {
+        if(xml_http.readyState == 4 && xml_http.status == 200){
+            //mi kacimo sadrzaj u <div>
+            document.getElementById(thediv).innerHTML = xml_http.responseText;
+        }
+    }
+    //open salje HTTP zahtev, prvi parametar je metoda, drugi URL adresa na koju se salje, treci true znaci da se izvrsava asihrono
+    //send samo za slanje http zahteva na server
+    xml_http.open('GET',thefile, true);
+    xml_http.send();
+}
+
+</script>
+
+</head>
+<body>
+    
+<input type="submit" onclick="load('anotherdiv','include.inc.php');">
+<div id="anotherdiv"></div>
+
+</body>
+</html>
\ No newline at end of file
diff --git a/exam175/index.php b/exam175/index.php
new file mode 100644
index 0000000..7b60297
--- /dev/null
+++ b/exam175/index.php
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+
+<script type="text/javascript">
+
+function findmatch(){
+    if(window.XMLHttpRequest){
+        xmlhttp =new XMLHttpRequest();
+    } else {
+        xmlhttp = new ActiveXObject('Microsoft.XMLHTTP');
+    }
+    
+    xmlhttp.onreadystatechange = function(){
+        if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
+            document.getElementById('results').innerHTML = xmlhttp.responseText;
+        }
+    }
+
+    xmlhttp.open('GET','search.inc.php?search_text=' + document.search.search_text.value ,true);
+    xmlhttp.send();
+    
+}
+
+
+</script>
+</head>
+<body>
+    
+<form id="search" name="search">
+    Type a name: <br>
+    <input type="text" name="search_text" onkeyup="findmatch();">
+
+</form>
+
+<div id="results"></div>
+</body>
+</html>
\ No newline at end of file
diff --git a/exam175/search.inc.php b/exam175/search.inc.php
new file mode 100644
index 0000000..3710dc7
--- /dev/null
+++ b/exam175/search.inc.php
@@ -0,0 +1,26 @@
+<?php
+
+$mysql_db = 'example_database';
+$mysql_host = 'localhost';
+$mysql_user = 'example_user';
+$mysql_pass = 'Kolosnjaj4321!';
+
+if(isset($_GET['search_text'])){
+    $search_text = $_GET['search_text'];
+}
+
+if(!empty($search_text)){
+    $con = mysqli_connect($mysql_host,$mysql_user,$mysql_pass);
+    if(mysqli_select_db($con,$mysql_db)){
+
+
+        $query = "SELECT `name` FROM `names` WHERE `name` LIKE '". mysqli_real_escape_string($con,$search_text) ."%'";
+        $query_run = mysqli_query($con,$query);
+        while($query_row = mysqli_fetch_assoc($query_run)){
+             echo $name = $query_row['name'] . '<br>';
+        }
+    }
+
+}
+
+?>
\ No newline at end of file
diff --git a/exam180/index.php b/exam180/index.php
new file mode 100644
index 0000000..1f92008
--- /dev/null
+++ b/exam180/index.php
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+
+<script type="text/javascript">
+
+function insert(){
+    if(window.XMLHttpRequest){
+        xmlhttp = new XMLHttpRequest();
+    } else {
+        xmlhttp = new ActiveXObject('Microsoft.XMLHTTP');
+    }
+
+    xmlhttp.onreadystatechange = function(){
+        if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
+            document.getElementById('message').innerHTML = xmlhttp.responseText;
+        }
+    }
+
+    parameters = 'text=' + document.getElementById('text').value;
+
+
+    xmlhttp.open('POST', 'update.inc.php', true);
+    xmlhttp.setRequestHeader('Content-type','application/x-www-form-urlencoded'); // slicno kao header() u php- u 
+    xmlhttp.send(parameters);
+
+}
+
+
+</script>
+
+
+</head>
+<body>
+
+Insert data: <input type="text" id="text">
+<input type="button" value="Submit" onclick="insert();">
+<div id="message"></div>
+    
+</body>
+</html>
\ No newline at end of file
diff --git a/exam180/update.inc.php b/exam180/update.inc.php
new file mode 100644
index 0000000..0e4bf4f
--- /dev/null
+++ b/exam180/update.inc.php
@@ -0,0 +1,25 @@
+<?php
+
+if (isset($_POST['text'])) {
+    $text = $_POST['text'];
+}
+
+$mysql_db = 'example_database';
+$mysql_host = 'localhost';
+$mysql_user = 'example_user';
+$mysql_pass = 'Kolosnjaj4321!';
+
+if (isset($_POST['text'])) {
+    $text = $_POST['text'];
+    if (!empty($text)) {
+        $con = mysqli_connect($mysql_host, $mysql_user, $mysql_pass);
+        if (mysqli_select_db($con, $mysql_db)) {
+            $query = "INSERT INTO `data` VALUES(NULL,'" . mysqli_real_escape_string($con, $text) . "')";
+            if ($query_run = mysqli_query($con, $query)) {
+                echo 'You are successfuly insert data in database';
+            }
+        } else {
+            echo 'not connected';
+        }
+    }
+}
diff --git a/exam185/throwEx.php b/exam185/throwEx.php
new file mode 100644
index 0000000..fc14a2d
--- /dev/null
+++ b/exam185/throwEx.php
@@ -0,0 +1,12 @@
+<?php 
+
+function divide($num1, $num2){
+    if($num2 == 0){
+        throw new Exception('Cannot devide by 0');
+    } else {
+        return $num1/$num2;
+    }
+}
+
+echo divide(10,0);
+?>
\ No newline at end of file
diff --git a/exam185/trycatch.php b/exam185/trycatch.php
new file mode 100644
index 0000000..523d130
--- /dev/null
+++ b/exam185/trycatch.php
@@ -0,0 +1,17 @@
+<?php 
+
+$age = 17;
+
+try {
+
+    if ($age > 18){
+        echo 'Old enough.';
+    } else {
+        throw new Exception('Not old enough');
+    }
+} catch(Exception $ex){
+    echo 'Error: '. $ex -> getMessage();
+}
+
+
+?> 
\ No newline at end of file
diff --git a/exam187/customErrorMessage.php b/exam187/customErrorMessage.php
new file mode 100644
index 0000000..a6f9aff
--- /dev/null
+++ b/exam187/customErrorMessage.php
@@ -0,0 +1,35 @@
+<?php
+
+$mysql_db = 'example_database';
+$mysql_host = 'localhost';
+$mysql_user = 'example_user';
+$mysql_pass = 'Kolosnjaj4321!';
+
+class DatabaseException extends Exception
+{
+    public function showSpecific()
+    {
+        return 'Error thrown on line' . $this->getLine() . ' in ' . $this->getFile();
+    }
+}
+class ServerException extends Exception
+{
+    public function showSpecific()
+    {
+        return 'Error thrown on line' . $this->getLine() . ' in ' . $this->getFile();
+    }
+}
+
+try {
+    if (!@$con = mysqli_connect($mysql_host, $mysql_user, $mysql_pass)) {
+        throw new ServerException();
+    } else if (!@mysqli_select_db($con, $mysql_db)) {
+        throw new DatabaseException();
+    } else {
+        echo 'Connected';
+    }
+} catch (ServerException $ex) {
+    echo  $ex->showSpecific();
+} catch (DatabaseException $ex) {
+    echo $ex->showSpecific();
+}
diff --git a/exam187/customEx.php b/exam187/customEx.php
new file mode 100644
index 0000000..e98d4b1
--- /dev/null
+++ b/exam187/customEx.php
@@ -0,0 +1,27 @@
+<?php 
+// Ovo mi ne radi ne znam iz kog razloga uvek baci error kad pogresim umesto da ispise poruku.
+$mysql_db = 'example_database';
+$mysql_host = 'localhosta';
+$mysql_user = 'example_user';
+$mysql_pass = 'Kolosnjaj4321!';
+
+class DatabaseException extends Exception{}
+class ServerException extends Exception{}
+
+try{
+    if(!$con = mysqli_connect($mysql_host,$mysql_user,$mysql_pass)){
+        throw new ServerException('Could not connect to server.');
+    } else if (!mysqli_select_db($con,$mysql_db)) {
+        throw new DatabaseException('Could not select database.');
+    } else {
+        echo 'Connected';
+    }
+
+} catch (ServerException $ex) {
+    echo 'Error: ' . $ex->getMessage();
+} catch (DatabaseException $ex) {
+    echo 'Error: ' . $ex->getMessage();
+}
+
+
+?>
\ No newline at end of file
diff --git a/exam190/index.php b/exam190/index.php
new file mode 100644
index 0000000..6e16eb5
--- /dev/null
+++ b/exam190/index.php
@@ -0,0 +1,31 @@
+<?php
+
+class BankAccount
+{
+    // modifikatori vidljivosti u PHP public, protected, private
+    public $balance = 42;
+
+    public function DisplayBalance()
+    {
+        return 'Balance: ' . $this->balance . '<br>'; // Ovako pristupamo vrednosti balance 'pravimo referencu'
+    }
+
+    public function Withdraw($amount)
+    {
+        if ($this->balance < $amount) {
+            echo 'Not enough money <br> ';
+        } else {
+            $this->balance = $this->balance - $amount;
+        }
+    }
+}
+
+//nova instanca klase
+$ba = new BankAccount;
+
+
+echo $ba->DisplayBalance();
+
+$ba->Withdraw(50);
+
+echo $ba->DisplayBalance();
diff --git a/exam193/index.php b/exam193/index.php
new file mode 100644
index 0000000..ee30468
--- /dev/null
+++ b/exam193/index.php
@@ -0,0 +1,22 @@
+<?php
+
+class BankAcount
+{
+    //ako stavimo protected ili private moci cemo da prikazemo promenljivu balance preko metoda.
+    private $balance = 20;
+
+    //ako stavimo protected ili private ne mozemo da pozovemo method DisplayBalance();
+    public function DisplayBalance()
+    {
+        return $this->balance;
+
+    }
+}
+
+$alex = new BankAcount;
+
+echo $alex->DisplayBalance();
+
+
+
+?>
\ No newline at end of file
diff --git a/exam194/constants.php b/exam194/constants.php
new file mode 100644
index 0000000..abf5d32
--- /dev/null
+++ b/exam194/constants.php
@@ -0,0 +1,22 @@
+<?php 
+
+//Area of circle
+
+class Circle{
+    public const pi = 3.14159265359;
+
+    public function CircleArea($r){
+        return self::pi * $r *$r;
+    }
+
+}
+
+$area = new Circle;
+
+echo 'if pi is '.Circle::pi . '<br>';
+
+
+
+echo 'Area of circle is ' . $area->CircleArea(3);
+
+?>
\ No newline at end of file
diff --git a/exam194/constructor.php b/exam194/constructor.php
new file mode 100644
index 0000000..df69d68
--- /dev/null
+++ b/exam194/constructor.php
@@ -0,0 +1,19 @@
+<?php 
+
+class Example{
+
+    public function __construct($something)
+    {
+        $this-> SaySomething($something);
+    }
+
+    public function SaySomething($something){
+        echo $something;
+    }
+}
+
+$example = new Example('Some text');
+
+
+
+?>
\ No newline at end of file
diff --git a/exam196/index.php b/exam196/index.php
new file mode 100644
index 0000000..2c1d038
--- /dev/null
+++ b/exam196/index.php
@@ -0,0 +1,43 @@
+<?php
+
+class BankAccount
+{
+    // modifikatori vidljivosti u PHP public, protected, private
+    public $balance = 0;
+
+    public function DisplayBalance()
+    {
+        return 'Balance: ' . $this->balance . '<br>'; // Ovako pristupamo vrednosti balance 'pravimo referencu'
+    }
+
+    public function Withdraw($amount)
+    {
+        if ($this->balance < $amount) {
+            echo 'Not enough money <br> ';
+        } else {
+            $this->balance = $this->balance - $amount;
+        }
+    }
+
+    public function Deposit($amount){
+        $this->balance = $this->balance + $amount;
+    }
+}
+
+//Multiple instances of class :
+$alex = new BankAccount;
+$billy = new BankAccount;
+
+$alex -> Deposit(100);
+$billy -> Deposit(50);
+
+$alex -> Withdraw(98);
+$billy -> Withdraw(12.5);
+
+echo $alex -> DisplayBalance();
+echo $billy -> DisplayBalance();
+
+
+
+
+?>
\ No newline at end of file
diff --git a/exam197/index.php b/exam197/index.php
new file mode 100644
index 0000000..0dc33ba
--- /dev/null
+++ b/exam197/index.php
@@ -0,0 +1,49 @@
+<?php
+
+class BankAccount
+{
+
+    public $balance = 0;
+    public $type = '';
+
+    public function SetType($input){
+        $this->type = $input;
+    }
+
+    public function DisplayBalance()
+    {
+        return 'Balance: ' . $this->balance . '<br>'; 
+    }
+
+    public function Withdraw($amount)
+    {
+        if ($this->balance < $amount) {
+            echo 'Not enough money <br> ';
+        } else {
+            $this->balance = $this->balance - $amount;
+        }
+    }
+
+    public function Deposit($amount){
+        $this->balance = $this->balance + $amount;
+    }
+}
+
+class SavingsAccount extends BankAccount {
+}
+
+$alex = new BankAccount;
+$alex->SetType('18-25 Current');
+$alex->Deposit(100);
+$alex->Withdraw(20);        
+
+$alex_savings = new SavingsAccount;
+$alex_savings -> Deposit(40);
+$alex_savings->SetType('Super Saver');
+
+
+echo $alex-> type .' has ' .$alex->DisplayBalance();
+echo $alex_savings->type .' has ' .$alex_savings->DisplayBalance();
+
+
+?>
\ No newline at end of file
diff --git a/exam199/index.php b/exam199/index.php
new file mode 100644
index 0000000..3b73963
--- /dev/null
+++ b/exam199/index.php
@@ -0,0 +1,28 @@
+<?php
+
+class DatabaseConnect{
+
+    public function __construct($db_host, $db_user, $db_pass)
+    {
+        echo 'Attempting connection...';
+
+        if(!$this->Connect($db_host,$db_user,$db_pass)){
+            echo 'Connection failed';
+        } else {
+            echo 'Connected to '. $db_host;
+        }
+    }
+
+    public function Connect($db_host, $db_user, $db_pass){
+        if(!mysqli_connect($db_host,$db_user,$db_pass)){
+            return false;
+        } else {
+            return true ;
+        }
+        
+    }
+}
+
+$conn = new DatabaseConnect('localhost','example_user','Kolosnjaj4321!');
+
+?>