Hello Sofia

Could be a number of reasons why the drop down doesn't happen. It could be code and security combined. I know Norton Web security 2000 firewall stops dropdown menus like yours if the user sets pop-ups to stop. If your a newbie well then welcome to scripting for various web browsers. What you code in one, more than too often doesn't work in the other. Take the code below that just shows and hides layers as an example. Before you even start writting the function you need to check wich browser the user is using like so:

Code:
if (ie4) {document.all[lay].style.visibility = "hidden";}
if (ns4) {document.layers[lay].visibility = "hide";}
if (ns6) {document.getElementById([lay]).style.display = "none";}
}
function showlayer(lay) {
if (ie4) {document.all[lay].style.visibility = "visible";}
if (ns4) {document.layers[lay].visibility = "show";}
if (ns6) {document.getElementById([lay]).style.display = "block";}
so you have to say "visible" in one, and "hide" for another..... and so on, I know it sucks but thats how it is.

My solution to you would be.. use Macromedia Fireworks, its awsome for drop down menus. And after that if your dropdown menus don't work you'll know it's a security issue.