function setFooter(){
	id = document.getElementById('footer_fix');
	
	if( window.innerHeight ){
			height = window.innerHeight-45;
	}else{
		height = document.documentElement. clientHeight-35;
	}
	
	defaultHeight = document.body.clientHeight;
	
	if(height>defaultHeight)
		id.style.bottom = "0px";
	else
		id.style.bottom = null;
}