onBeforeDragIn

fires before a dragged element is moved over the droppable area

Example

some.attachEvent("onBeforeDragIn", function(context, native_event){
    //... some code here ... 
});

The drag-and-drop context can have the following properties:

• from - the source object
• to - the target object
• source - the ID of the dragged item(s)
• target - the ID of the drop target, null for dropping on empty space
• start - the ID from which drag-n-drop was started