重写此代码，因为serialize（）不起作用

Question

I have this ajax jquery code:

var form = document.getElementById('frm');
            var data_string = form.serialize();
            $.ajax({
                type:       "POST",
                url:        "my_php_file.php",
                data:       data_string,
                success:    function(data) {

                }//end success function
            }) //end ajax call

This is in an external file called ajax.js.

I include ajax.js into an html file called "show.html". I also include jquery.js into show.html

I have tried getting the serialize to work, but the code is terminated right before executing the serialize. I have no idea why. But I am sure that it is the serialize which is causing it.

Is it possible to make some easy modification to this, so it doesn't use serialize?

Thanks

UPDATE:

This code (from answer below) seems to work partially also, when I alert the "form" variable, the message says "HTML Form Object" so it finds the form. Then when I alert the "data_string" variable, the message says "frm=undefined".

Any ideas why?

var form = document.getElementById('frm');
var data_string = $(form).serialize();

Answer 1

The serialize() method comes from jQuery. Your statement is failing because form isn't wrapped in jQuery:

var form = $('#frm');
var data_string = form.serialize();

Or:

var form = document.getElementById('frm');
var data_string = $(form).serialize();

Answer 2

My guess is that you're referencing the "Traditional" DOM object using getElementByID and not using it through jQuery (which would traverse the form and add the information). Try using:

var data_string = $('#frm').serialize();