Question

  <script type="text/javascript">
  $().ready(function() {
 jQuery.validator.addMethod("captcha", function(value, element)  {
       $.ajax({ url: "verifyCap.php",
                type: "GET",
                data: "txtCaptcha="+value,
                success:        
                     function(msg) { 
                         if(msg == "true")
                               return true;  // already exists
                         return false; 
                        }
                  });
    },"");
// validate signup form on keyup and submit
$("#signupForm").validate({
    rules: {
        title: "required",
        contactname: "required",
        email: {
            required: true,
            email: true
        },
        comment: "required",
        txtCaptcha:{
            required: true,
            captcha: true
        }
    },
    messages: {
        contactname: "Please enter your contact name",
        email: "Please enter a valid email address",
        comment: "Please enter your system requierment",
        txtCaptcha: {
            required:"Please enter verification code",
            captcha: "The verification code is incorrect"
        }
    }
});
});

My verifyCap.php

<?php
 session_start ();
 if ($_SERVER ["REQUEST_METHOD"] != "GET")
  die ( "You can only reach this page by posting from the html form" );
 if (($_GET ["txtCaptcha"] == $_SESSION ["security_code"]) && (! empty ( $_GET ["txtCaptcha"] ) && ! empty ( $_SESSION ["security_code"] ))) {
   echo  "true";
 } else {
     echo "false";
}
 ?>

My problem might due to the response format it is not true or false, but i print out whole verifyCap code. Anyone can help?

Answer 1

An ajax request does an get by default instead of a post. Change:

if ($_SERVER ["REQUEST_METHOD"] != "POST")

to

if ($_SERVER ["REQUEST_METHOD"] != "GET")

besides that, do not use $_REQUEST to get your data. Use $_GET instead.

You could also add some settings your ajax request:

   type: "POST",
   data: "your params here",