I know this question was asked many times, but it's still unfigurable for me. Anyway I have a code like this:
<div id="header">
Here are many different div's with various position (relative, absolute, static, etc).
</div>
<div id="content">
<div class="row">
<div class="inner">
<div class="upper">
Some dummy content
</div>
<div class="lower">
</div>
</div>
</div>
</div>
Now, how can I set for example .upper
div to fit into the window, since I have no idea what's the height of header?