Ajax POST无法使用Jquery和PHP

I am new to Jquery. I am trying to post a form to a php file using Jquery Post, I did a var_dump($_POST) in the php file but i can see only an empty array ( saw using firebug net), but i am coming back to the success function of Jquery. May be I am doing some thing silly..All the Javascript behaviour is working as expected except this problem. Somebody please help

$(document).ready(function() {

    //if submit button is clicked
    $('#submit').click(function () {       

        //show the loading sign
        $('#example').modal('show') ; 


        //start the ajax
        $.ajax({
            //this is the php file that processes the data 
            url: "mvc/process_form.php",

            //GET method is used
            type: "POST",


            //Do not cache the page
            cache: false,

            //success
            success: function (html) {             
                //if process_form.php returned 1/true (process success)

                if (html==1) {                 
                    //hide the form
                    $('.form').fadeOut('slow');                

                    //show the success message
                    $('.done').fadeIn('slow');

                //if process.php returned 0/false (send mail failed)
                } else alert('Sorry, unexpected error. Please try again later.');              
            }      
        });

        //cancel the submit button default behaviours
        return false;
    });
}); 

You need to pass form data as serialize. right now you are not passing form data into your ajax function.

Here you go:

$(document).ready(function() {

    //if submit button is clicked
    $('#submit').click(function () {       

        //show the loading sign
        $('#example').modal('show') ; 


        //start the ajax
        $.ajax({
            //this is the php file that processes the data 
            url: "mvc/process_form.php",

            //GET method is used
            type: "POST",
            data: $("#testform").serialize(),

            //Do not cache the page
            cache: false,

            //success
            success: function (html) {             
                //if process_form.php returned 1/true (process success)

                if (html==1) {                 
                    //hide the form
                    $('.form').fadeOut('slow');                

                    //show the success message
                    $('.done').fadeIn('slow');

                //if process.php returned 0/false (send mail failed)
                } else alert('Sorry, unexpected error. Please try again later.');              
            }      
        });

        //cancel the submit button default behaviours
        return false;
    });
}); 

you are not passing any $_POST data in your ajax function. http://api.jquery.com/jQuery.ajax/

Try this also:

var url = "mvc/process_form.php", 
   data = {hello: hello}; 
$.post(url,data, 
      function (status)
      {
         alert(status);
      }
 );