I made a dropdown menu and below that is a flash intro.
I tested on my Mac using Firefox and it looks fine BUT when I test it in PC using Firefox and IE, the flash intro covers my dropdown sub menu.

how to get rid of that?

NEED HELP PLZ!! this is very frustrating...... im ready to go out and yell my throat out... been fixing this for days.......

<style type="text/css">

#dd {
padding: 0 0 0 0;
margin: 0 0 0 0;
}

#dd li {
margin: 0;
padding: 0;
list-style: none;
float: left;
font: 11px arial;
}

#dd li a.menu {
display: block;
text-align: center;
background: #1F3D5C;
margin: 0 0px 0 0;
color: #FFF;
width: 160px;
text-decoration: none;
padding: 2px 2px;
}

#dd li a.menu:hover {
background-color: #769888;
}

.submenu {
background: #EAEBD8;
border: 1px solid #5970B2;
visibility: hidden;
position: absolute;
z-index: 3;
width:160px;
}

.submenu a {
display: block;
font: 11px arial;
text-align: left;
text-decoration: none;
color: #2875DE;
padding: 1px;
z-index: 3;
}

.submenu a:hover {
background: #49A3FF;
color: #FFF;
z-index: 3;
}
</style>

It's hard to make out what is going on from your supplied code. If you suppy a link to the page i'm sure we can help. I've suffered this sort of problem before.

I finally solved the problem.
My .swf wasnt in transparent mode so i change the wmode into transparent in the publish setting and now it works!