IFrame problem IE ONLY

[Ini]

Well, I made a website for my friend and it has an iframe (not transparent). It worked perfectly fine (i use mozilla) but he told me at school that the iframe was just plain white. I tried reuploading the files, but it doesn't work. I tried Mozilla and Opera, they both work.

Please help, is this just a browser problem or can I fix it?

[Twey]

You mean you want the iframe to be transparent, but it isn't?

[Ini]

No, i mean the iframe has a background, but instead of showing ANY content it's just a plain block of white. It's not supposed to be transparent, the IFRAME just doesn't show up correctly.

[Ini]

I made another web page with another iframe in the middle, but it works! I think it has something to do with using PHP in the iframe, cause i have no php in the other one. Does this mean I can't use PHP if I want it to work in IE?

Edit: sorry for double post