function moveHandler(evt)
	{
		if (start != null)
		{
			var pt = new mxPoint(mxEvent.getClientX(evt), mxEvent.getClientY(evt));
			onChange(Math.max(0, initial + ((horizontal) ? (pt.x - start.x) : (start.y - pt.y)) - dx));
			mxEvent.consume(evt);
			
			if (initial != getValue())
			{
				ignoreClick = true;
				last = null;
			}
		}
	}
Updates the states of the given undo/redo items.