PHP generated verification code and Verification Code verification complete instance

Title Document

<! DOCTYPE HTML PUBLIC "-//w3c//dtd XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >  xmlns= "http://www.w3.org/1999/xhtml" >  http-equiv= "Content-type" content= "text/html; Charset=utf-8 "/> <title> Untitled document </title> <script language= "JavaScript" > Function Refresh_code () {form1.imgcode.src= "verifycode.php?a=" +math.random (); } </script>  Id= "Form1" Name= "Form1" method= "Post" action= "checkcode.php" > <label For= "Code" > Verification Code:</label> <input Type= "text" name= "code" id= "TextField"/>  Id= "Imgcode" src= "verifycode.php" alt= "Verification Code"/> <a Href= "Javascript:refresh_code ()" > Can't see clearly? Change a </a> <input Type= "Submit" name= "button" id= "button" value= "Submit"/> </form> </body>

The verifycode.php file code is as follows

<?php/* Picture Verification Code Powered by Kason test <a href= "http://www.hzhuti.com/nokia/c6/" > Http://www.hzhuti.com/nokia/c   6/</a> */session_start ();   $num =4;//Verification Code number $width =80;//Verification code width $height =20;//Verification code Height $code = "; for ($i =0; $i < $num; $i + +)//Generate verification Code {switch (rand (0,2)) {case 0: $code [$i]=CHR (rand (48,57)); break;//Digital case 1: $code [$i]=CHR (rand (65,90)); break;//Capital Letter Case 2: $code [$i]=CHR (rand (97,122)); break;//Small Letter}} $_session["Verifycode"]= $code;   $image =imagecreate ($width, $height);   Imagecolorallocate ($image, 255,255,255);    for ($i =0; $i <80; $i + +)//Generate interference pixels {$dis _color=imagecolorallocate ($image, Rand (0,2555), Rand (0,255), Rand (0,255));   Imagesetpixel ($image, rand (1, $width), rand (1, $height), $dis _color); } for ($i =0; $i < $num; $i + +)//print characters to image {$char _color=imagecolorallocate ($image, Rand (0,2555), Rand (0,255), rand (0,255)    );   Imagechar ($image, Max, ($width/$num) * $i, Rand (0,5), $code [$i], $char _color);   } header ("Content-type:image/png"); Imagepng ($image);//output image to browser Imagedestroy ($image);//Release Resources?>

checkcode.php files are as follows

<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 " /> <?php ini_set (' display_errors ', ' Off ');   Session_Start ();   if ((Strtoupper ($_post["code")) ==strtoupper (($_session["Verifycode"])) {print ("captcha correct,");   }else{Print ("Captcha error,"); } Echo "submitted Captcha:". Strtoupper ($_post["code"]). ", correct captcha:". Strtoupper ($_session["Verifycode"]);?>

PHP generated verification code and Verification Code verification complete instance