function initFooter(){
	var main = document.getElementById('main');
	var footer = document.getElementById('cat_footer');

	if (main && footer){
		main.style.height = 'auto';
		if ((main.offsetHeight + footer.offsetHeight) < document.documentElement.clientHeight){
			main.style.height = document.documentElement.clientHeight - footer.offsetHeight + 'px';
		}
	}
}

window.onload = initFooter;
window.onresize = initFooter;