PHP Captcha and reCaptcha options for web forms using javascript

Hi friends,
This is a simple code to build a captcha code with recaptcha options with simple javascript and PHP code. Now a days SPAM messages are increasing. To stop the SPAM and validating the forms with using this simple captcha code. This post explains how to build a simple captcha using javascript, php with few steps.

PHP Captcha and reCaptcha options for web forms using javascript | Anil Labs

PHP Code:

<?php
//Start the session so we can store what the security code actually is
session_start();

//Send a generated image to the browser
create_image();
exit();

function create_image()
{
//Let's generate a totally random string using md5
//$md5_hash = md5(rand(0,999));
//We don't need a 32 character long string so we trim it down to 5
// $security_code = substr($md5_hash, 15, 4);

$security_code = rand(1000,9999);
//Set the session to store the security code
$_SESSION["security_code"] = $security_code;

//Set the image width and height
$width = 120;
$height = 35;

//Create the image resource
$image = ImageCreate($width, $height);

//We are making three colors, white, black and gray
$white = ImageColorAllocate($image, 255, 255, 255);
$black = ImageColorAllocate($image, 0, 0, 0);
$grey = ImageColorAllocate($image, 204, 204, 204);

$red = ImageColorAllocate($image, 252, 0, 0);

//Make the background black
ImageFill($image, 0, 0, $white);

//Add randomly generated string in white to the image
//ImageString($image, 5, 40, 7, $security_code, $white);
$font = 'font1.ttf';
imagettftext($image, 18, 0, 15, 28, $red, $font, $security_code);
//Throw in some lines to make it a little bit harder for any bots to break
ImageRectangle($image,0,0,$width-1,$height-1,$grey);
//imageline($image, 0, $height/2, $width, $height/2, $grey);
//imageline($image, $width/2, 0, $width/2, $height, $grey);

//Tell the browser what kind of file is come in
header("Content-Type: image/jpeg");

//Output the newly created image in jpeg format
ImageJpeg($image);

//Free up resources
ImageDestroy($image);
}
?>