CAPTCHA -- Completely Automated Public Turing test to tell Computers and Humans Apart

Php Captch

Validate  



A CAPTCHA is a type of challenge-response test used in computing as an attempt to ensure that the response is generated by a person. The process usually involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are assumed to be unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human.

//open dier

  $dir=opendir("Demo/ads/");

//get each file and exclude some stuffs

 while($file=readdir($dir))

 {

  if($file!="."&&$file!="..")

  {

 $stringarray = $stringarray.$file. " ";

  }//end of if

 }//end of while($file=readdir($dir))

 //convert string "array" into "real array"

$filearray = explode(" ",$stringarray);

$count = count($filearray)-2;

 //create random number

 $rand=rand(0,$count);

 //show an add

 echo "

<a href='adgo.php?ad=$filearray[$rand]'><img src='Demo/ads/$filearray[$rand]' border=0></a>

 ";

//Html Code Start Here

<p>Please Wait... <!--<meta http-equiv='refresh' content='3'> -->

<a href="">Click Here To Refresh Page</a>



Index.php

$ad=$_GET['ad'];
switch($ad)

{

  case "ad1.gif";

  header ("Location: http://www.google.co.in");

  break;

  

  case "ad2.gif";

  header ("Location: http://www.yahoo.com");

  break;

}//end of switch