Width Problem

Having an issue with multiple divs…

I have one div that’s 800px and contains two more. For the time being I’m skipping all the code just to give you a quick idea. It’s not really necessary for my answer, anyhow:

<div 800px wide>

<div 250px wide display:inline></div>
<div —– wide? display:inline></div>

</div>

Here’s my problem. I want the second INTERIOR div to take up 100% of the available width (800-250 and whatever margin/padding). Problem: width:100% will cause it to mess up the whole format. I can’t manually give it a pixel width because I don’t know the EXACT number since margins/padding/etc changes, as well as the fact I don’t WANT to input an exact width each and every time.

Any help? Thx a bunch

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