$(document).ready(function()
{
	resizeBody();
	
	$(window).resize(resizeBody);
});

function resizeBody()
{
	var freeSpace = $(window).height() - ($('#header').outerHeight() + $('#footer').outerHeight());
	var padding = (freeSpace - $('#body').height());
	var paddingCSS = (padding / 2) + 'px 0px';
	
	if(padding > 30)
		$('#body').css('padding', paddingCSS);
}