<frameset rows="*,*">
<frame src="banner.html" name="banner">
<frame src="content.html" name="content">	

Hard to specify the height of the top frame to get neither no more than is needed nor less. Less, remember, is not exactly lovely if one has to scroll where it is a company banner that is in question.

Perhaps avoid the problem altogether by having the banner a pic with a fixed height that informs you how to set the top frame. Otherwise, just living with generous space. Or don't use frames!