Dhtml menu

Hello

I am designing a simple dhtml /java script menu. I got the code and made changes.

the background of the menu is so light tat the everything below the menu is visible.

for eg. if we look at this menu on page

http://www.milonic.com when we move the mouse over the links on top(About Milonic) then the letter below the menu is a bit visible.

I know the fix to it is to put another layer so that nothing is visible below the layer.

but i have no clue how to do that.

any kind of help will be great.

Thanks
Sai