File: php_captcha.php
<?php session_start(); $RandomStr = md5(microtime()); $ResultStr = substr($RandomStr,0,5); $NewImage =imagecreatefromjpeg("img.jpg");
$LineColor = imagecolorallocate($NewImage,233,239,239); $TextColor = imagecolorallocate($NewImage, 255, 255, 255);
imageline($NewImage,1,1,40,40,$LineColor); imageline($NewImage,1,100,60,0,$LineColor); imageline($NewImage,5, 1, 200, 50, $LineColor);
imagestring($NewImage, 5, 15, 5, $ResultStr, $TextColor);
$_SESSION['key'] = $ResultStr; header("Content-type: image/jpeg"); imagejpeg($NewImage);
?>File: form.php
<?php session_start();?>
<html> <head> <title>PHP-CAPTCHA </title> </head> <body onload="return focuson();"> <script language="javascript"> function focuson(){ document.form1.number.focus() }
function check(){ if(document.form1.number.val ue==0){ alert("Please enter your Category Name"); document.form1.number.focus(); return false; } }
</script><?php if(isset($_REQUEST['Submit'])){ $key=substr($_SESSION['key'],0,5); $number = $_REQUEST['number']; if($number!=$key){ echo ' Validation string not valid! Please try again!'; }else{ echo 'Your string is valid!'; } }
?>
<form name="form1" method="post" action="form.php" onsubmit="return check();"> <img src="php_captcha.php" /></td> <input name="number" type="text" id="number" /></td> <input name="Submit" type="submit" value="Submit" /></td> </form> </body></html>