function pageHeight()
{
	var bodyHeight = document.body.clientHeight;
	var windowHeight = document.documentElement.clientHeight;
	windowHeight = windowHeight -10;
	var body = document.getElementById('main');
	if (windowHeight > bodyHeight)
	{
		body.style.height = windowHeight + 'px';
	}
	else
	{
		body.style.height = bodyHeight + 'px';
	}

}