Help with DropDown

ok so i got a layout that looks perfect but i need help.

The Drop down menu works in IE but it doesnt work in FF so in IE when i scroll over the image it works but in FF it doesnt this is the code for the menu.js


function dropdown(menuitem)
{
document.getElementById(menuitem).style.display = "block";
return false;
}
function dropout(menuitem)
{
document.getElementById (menuitem).style.display = "none";
return false;
}

It just doesnt work in FF can anyone help me please.

Can you show me a live version?