Jquery, getting DIV ID as it is being dragged using "draggable"?

I found another post about this but the solution there isn't working for me... I am trying this (having already instantiated the draggable option separatel开发者_StackOverflowy:

 $( ".masker" ).bind( "drag", function(event, ui) {

  testdragging =    ui.draggable.attr('id') ;


}); 

Just calling this: ui.draggable.attr('id') ; makes the entire class of DIV not draggable, if I simply remove this then it works fine, just can't figure this out, any advice is appreciated.

---

In the case of draggable (not viewing it from the droppable side) it's ui.helper instead of ui.draggable, like this:

$(".masker").bind("drag", function(event, ui) {
  testdragging = ui.helper.attr('id');
}); 

You can test it out here.