Hi all,

I have been trying to get my head around this for awhile now, but cant seem to work out this last little bit.

Let me explain what I'm doing.

I have an events page where someone can enrol for an event, when they click "Enrol" it takes them to a form which has been populated with things like the date, location, etc for the event. They can then enter missing details like their names, email address, etc.

I am using the following to achieve the above:

//Function for adding subject to subject box
   if($('#Form_Form').length > 0){
      var course = decodeURIComponent($.getUrlVar('cour'));
      var date = decodeURIComponent($.getUrlVar('date'));
      var time = decodeURIComponent($.getUrlVar('time'));
      var loc = decodeURIComponent($.getUrlVar('loc'));
      var price = decodeURIComponent($.getUrlVar('price'));
      if(course != 'undefined'){
         $('#EditableRadioField39').hide();
         $('#Form_Form_EditableTextField40').val(course);
      } else {
         $('#EditableTextField40').hide();
      }
      if(date != 'undefined'){
         $('#Form_Form_EditableDateField13').val(date);
      }
      if(time != 'undefined'){
         $('#Form_Form_EditableTextField12').val(time);
      }
      if(loc != 'undefined'){
         $('#Form_Form_EditableTextField14').val(loc);
      }
      if(price != 'undefined'){
         $('#Form_Form_EditableTextField36').val(price);
      }
   }

The only issue I have is that I need to make something that changes the price dependent on how many people sign up for the event.

I cant seem to create a new function which works.

how can I work out if a EditableTextField has nothing assigned to it?

The following is what I am trying:

if($('#EditableTextField21').var != ''){
   $('#Form_Form_EditableTextField36').val(price*2);
}

EditableTextField21 is a text field for the persons Name.
EditableTextField36 is a field for the price.

you're right, my mistake.

However it doesn't automatically update when something is entered into "#EditableTextField21".

Make sure you function is included within a change event that is fired when you edit the field.

$("#EditableTextField21").change(function() {
// do something
});

Lot's of docs on the web for how to use events in javascript - http://www.codecademy.com/courses/jquery-events/1#!/exercises/0