Why is my dropdown transparent in IE7

[FancyPrairie]

I have set the background-color to white for the dropdown and have set the z-index property to 3000. But it is still transparent and falls behind other controls. My code looks something like this:

<div ...>
<select style="z-index: 3000; background-color: white; overflow: visible...></select>
.....
</div>

What am I doing wrong?

 

[FancyPrairie]

Nevermind. My z-indexes were not correct for other div tags on the page.