function resize_footer()
{
	var y = 0;
	if (self.innerHeight)
	{
		y = self.innerHeight;
	}
	else if (document.documentElement && document.documentElement.clientHeight)
	{
		y = document.documentElement.clientHeight;
	}
	else if (document.body)
	{
		y = document.body.clientHeight;
	}
	
	var divh = document.getElementById('main_menu').offsetHeight;
	if (y<divh+505)
	{
		document.getElementById('footer').style.height=30+"px"
		document.getElementById('footer').style.position="relative"
	}
}