add: if (!this.mouse.now.x || !this.mouse.now.y) return false; 
context: 	checkAgainst: function(el){		el = el.getPosition();		return (this.mouse.now.x > el.left && this.mouse.now.x < el.right && this.mouse.now.y < el.bottom && this.mouse.now.y > el.top);	},
meta: 6317	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/6317/6d2f5a3deaeca4e2cafd8a814b68552bd0c11c30/Drag.Move.js/clean/Drag/Drag.Move.js