<?php 


session_start();
//header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); 
//header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); 
//header("Cache-Control: no-store, no-cache, must-revalidate"); 
//header("Cache-Control: post-check=0, pre-check=0", false);
//header("Pragma: no-cache"); 

function _generateRandom($length=6)
{
    $_rand_src = array(
        array(48,57) //digits
        , array(97,122) //lowercase chars
//        , array(65,90) //uppercase chars
    );
    srand ((double) microtime() * 1000000);
    $random_string = "";
    for($i=0;$i<$length;$i++){
        $i1=rand(0,sizeof($_rand_src)-1);
        $random_string .= chr(rand($_rand_src[$i1][0],$_rand_src[$i1][1]));
    }
    return $random_string;
}

$im = @imagecreatefromjpeg("image.jpg"); 
$rand = _generateRandom(3);
$_SESSION['captcha'] = $rand;
ImageString($im, 5, 2, 2, $rand[0]." ".$rand[1]." ".$rand[2]." ", ImageColorAllocate ($im, 0, 0, 0));
$rand = _generateRandom(3);
ImageString($im, 5, 2, 2, " ".$rand[0]." ".$rand[1]." ".$rand[2], ImageColorAllocate ($im, 255, 0, 0));
Header ('Content-type: image/jpeg');
imagejpeg($im,NULL,100);
ImageDestroy($im);



//session_start();
//header("Expires: Mon, 26 Jul 2011 05:00:00 GMT"); 
//header("Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT"); 
//header("Cache-Control: no-store, no-cache, must-revalidate"); 
//header("Cache-Control: post-check=0, pre-check=0", false);
//header("Pragma: no-cache"); 

//function generate_captcha($length=6)
//{
//    $random_source = array(
//        array(48,57) //digits
 //       , array(97,122) //lowercase chars
//        , array(65,90) //uppercase chars
//    );
//    srandom ((double) microtime() * 1000000);
//    $random_string = "";
//    for($i=0;$i<$length;$i++){
 //       $i1=rand(0,sizeof($random_source)-1);
 //       $random_string .= chr(rand($random_source[$i1][0],$random_source[$i1][1]));
//    }
//    return $random_string;
//}

//$image = @imagecreatefromjpeg("captcha.jpg"); 
//$random = generate_captcha(3);
//$_SESSION['captcha'] = $random;
//ImageString($image, 5, 2, 2, $random[0]." ".$random[1]." ".$random[2]." ", ImageColorAllocate ($image, 0, 0, 0));
//$random = generate_captcha(3);
//ImageString($image, 5, 2, 2, " ".$random[0]." ".$random[1]." ".$random[2], ImageColorAllocate ($image, 255, 0, 0));
//Header ('Content-type: image/jpeg');
//imagejpeg($image,NULL,100);
//ImageDestroy($image);

?> 

 