Iframe shimming opacity in IE6

Hi,

I have a tooltip kind of box that popups on hover, but the IE6 windowed control select box overlaps it. So, I have to resort to iframe shimming.

I have an absolutely positioned iframe of exactly same size as select box over it and that below my tooltip. It works as intended. However, I have to have iframe transparent so that the user can see the select underneath it, otherwise it’d be same as hiding the select box. So, I give iframe filter:alpha(opacity=0); while it works, it also makes opacity of the select box beneath the iframe invisible. This works as intended in IE 7 though, but IE7 doesn’t have the select overlap issue so that’s not a consolation - and besides I’ll restrict the fix to IE6 alone thorough conditional statements anyway.

So, could anyone suggest how to make opacity of iframe alone invisible and not anything underlying?

Guess thats the way IE6 behaves and probably no workaround. In the end I dynamically positioned and resized the iframe to cover only the tooltip area.