Help I'm stuck, creating the most basic extension

Help I'm stuck, creating the most basic extension

Hi I need some help making a simple jQuery extension.

I like the way you can use jQuery without any javascript in the HTML. I do this by creating keywords for class names that fire up some jQuery code. Sometimes I want to pass some data and in anchor I use the rel or otherwise the title. But sometimes the rel attribute is unavailable and you dont want the data to show as a title. So I'm passing this data as a extra class name. for instance
<input name="test" class="jSubmitOnUpdate jData:nameOfTheForm" />
. It's not the nicest example as I can easily check the form in which it recides.

This jQuery code is what is fired by the class names (also just to illustrate, but it also works):
   // SUBMITONUPDATE: submits the form defined in rel when the field is updated
   $('.jSubmitOnUpdate[class*="jData:"]').change( function(event) {
      var arrayOfClasses = $(this).attr('class').split(' ');
      for (var key in arrayOfClasses) {
         if (arrayOfClasses[key].indexOf('jData:') >= 0) {
            // Get data
            var data = arrayOfClasses[key].replace('jData:','');
            break;
         }
         $(data).submit();
      }
   });


What I want to do is build a small reusable extension for jQuery that gets my data when I pass it, like this.
   $('.jSubmitOnUpdate[class*="jData:"]').change( function(event) {
      var data = $(this).jData();
      $(data).submit();
   });


I read some article on how to build one and made this:

// jQuery extension: jData
(function($){
    $.fn.extend({
        jData: function() {
         var arrayOfClasses = $(this).attr('class').split(' ');
         for (var key in arrayOfClasses) {
            if (arrayOfClasses[key].indexOf('jData:') >= 0) {
               // Get data
               var data = arrayOfClasses[key].replace('jData:','');
               return data;
            }
         }           
        }
    });
})(jQuery);


But I also read abot passing back the jquery object....and there's where I got stuck...so, please...Help, I'm stuck!