Position.GetWindowSize = function(w) {
        w = w ? w : window;
        var width = w.innerWidth || (w.document.documentElement.clientWidth || w.document.body.clientWidth);
        var height = w.innerHeight || (w.document.documentElement.clientHeight || w.document.body.clientHeight);
        return [width, height]
}

Event.observe(window, 'load', function() { footer() });

function footer() { 
	var dim = Position.GetWindowSize(); 
	var hgt = dim[1];
	var cnt = $('s-content').getHeight() + 78;
	if(cnt < hgt) {
		$("s-content").setStyle({
			height: hgt+'px'
			});
		}
	}