popup menu at header frame cannot overlap to bottom frame help

[pasupathy]

hello there,

I have the following problem with this pop up menu and unable to solve
therefore please help me out.

an index file, consists of a top and bottom frame.
In the top frame there is a pop up menu, when click the menu , the drop
down list is being overlapped by the bottom frame.

How can I code it in such a way the drop down menu overlaps the bottom frame

I am using dreamweaver and fireworks........... cant attach the html
file here