Problems with layers in dreamweaver

Hi people. I have made this menu using layers in dreamweaver. When the window is maximized, the layers are positioned in they way that I want them to be. But the moment I resize the window to a very small size, the layers go out of position. The example is here :

http://www12.brinkster.com/abichapkongsee/html/enquiry.htm

can someone offer any solution to this? Thanks!