Resolution width and positioning

[Steve25]

I'm having problems with a page that i am doing that uses a header with 100% width and divs positioned by % as well. So for example on the top part of the page i have a div that's positioned 80% left of it. At first i was using relative positioning but i got told that's bad to do in my case. The problem i have is when i go into different resolutions the whole thing gets messed up. The bit i am talking about at the top goes off too far to the right and when you scroll over the header doesn't extend. Here is my code for the top div part:

#top-div {
height: 20px;
margin-left: 80%;
padding: 10px;
width: 250px;
}

Thanks for any help

[PeejAvery]

The code you provided is hardly enough to assess the whole problem. Could you post screenshots of what you want it to look like, and what happens? This would really help to go along with your description.