If you want to customize the size of the "window" created by FancyBox to hold content, there is an easy method built in for that. Visit the website for more detailed instructions, but here's a tip:
// Set up popup iframe (fancybox)
$(".yourframeclass").fancybox({
'autoDimensions': false,
'padding' : 0,
'width' : 940,
'height' : 400,
'autoScale' : false,
'transitionIn' : 'none',
'transitionOut' : 'none',
'type' : 'iframe'
});
In this example, I'm configuring a popup with dimensions of 940px by 400px (you can also use percentage values)... If the content exceeds the size of the fancybox holder, scroll bars will appear within the box itself rather than on the entire document!!!