code: function updateFingerData(evt) {
  			
  			var id = evt.identifier!==undefined ? evt.identifier : 0; 
  			var f = getFingerData( id );
  			
  			f.end.x = evt.pageX||evt.clientX;
  			f.end.y = evt.pageY||evt.clientY;
  			
  			return f;
  		}
docs: Updates the finger data for a particular event object
  @param {object} evt The event object containing the touch/finger data to upadte
  @return a finger data object.
  @inner