用ajax写的下拉式菜单。有两种效果，一是鼠标点击下拉，二是鼠标经过时下拉。-Ajax written with the drop-down menu. There are two effects, one mouse click on the drop-down, and the other is a result of the drop-down mouse.

Jquery 下拉菜单网页控件源代码!Javascr ipt 开发的源代码!