Ajax表单不起作用

Somehow my form is not working. Anyone knows why? Seems like ajax is not kicking in at all, because the action kicking in is data.php and not data_ajax.php, which I should see if ajax is working.

EDIT

Changed the HTML to what it actually looks like, though it should be the same result.

HTML

<div id="hidden_slidersize"></div>
<script type="text/javascript">
$(function(){
if ($('body').width() >= 960) {
var sizeOfSlider = 500;
} else {
var sizeOfSlider = ($('body').width())/2;
}
$('#hidden_slidersize').html('<form id="dataform" method="post" name="hiddentrick_form" action="data.php"><fieldset><input id="hiddentrick" name="hiddentrick" type="hidden" value="' + sizeOfSlider + '" /><input class="datasubmit" type="submit" value="senddata" /></fieldset></form>');
});
</script> 

Script

$(document).ready(function() {

var form = $('form#dataform');

      form.submit(function () { 

    $.ajax({  
      type: 'POST',  
      url: 'data_ajax.php',  
      data: form.serialize(),
      dataType:'html',  
      success: function(data) {alert('yes');},
      error: function(data) {
      //AJAX request not completed
      alert('no');
      }
    });  
    return false;  

      });
}); 

You need to use .on() method because your content is loaded dynamically.

$(document).ready(function() {

$(document).on('submit', 'form#dataform', function () { 

    $.ajax({  
      type: 'POST',  
      url: 'data_ajax.php',  
      data: form.serialize(),
      dataType:'html',  
      success: function(data) {alert('yes');},
      error: function(data) {
      //AJAX request not completed
      alert('no');
      }
    });  
    return false;  

      });
});