METHOD:

This page is a sample of CSS menu valid on Firefox, Opera & Konqueror :

1. display an inline list;
2. each menu element is a li;
3. each submenu is a list contain in the – upper – li element;
4. by default they are positionned on the left of the viewport using absolute position and left property as follow: position: absolute; left: -999em;
5. On a mouseover on the menu element, we modify left property to left: 0em; (not auto !);
6. We also need to specify that menu element are position: relative; elseif the block is positionned to the left of the document.

Don't forget to make accessible website using accesskey, alt, title.