function showLoginOverlay(){
	document.getElementById('login_fader').style.display = 'block';
	document.getElementById('login_fader').style.height = getPageHeight() + 'px';
	document.getElementById('login_overlay').style.display = 'block';
	document.getElementById('login_box').style.marginTop = getYScroll() + 100 + 'px';
	document.getElementById('login').focus();
}
function hideLoginOverlay(){
	document.getElementById('login_fader').style.display = 'none';
	document.getElementById('login_overlay').style.display = 'none';
}
function getYScroll(){
	var yScroll = 0;
	if(self.pageYOffset){
		yScroll = self.pageYOffset;
	}else if(document.documentElement && document.documentElement.scrollTop){
		yScroll = document.documentElement.scrollTop;
	}else if(document.body){
		yScroll = document.body.scrollTop;
	}
	return yScroll;
}
function getPageHeight(){
	var yScroll;
	if(window.innerHeight && window.scrollMaxY){
		yScroll = window.innerHeight + window.scrollMaxY;
	}else if(document.body.scrollHeight > document.body.offsetHeight){
		yScroll = document.body.scrollHeight;
	}else{
		yScroll = document.body.offsetHeight;
	}
	var windowHeight;
	if(self.innerHeight){
		windowHeight = self.innerHeight;
	}else if(document.documentElement && document.documentElement.clientHeight){
		windowHeight = document.documentElement.clientHeight;
	}else if(document.body){
		windowHeight = document.body.clientHeight;
	}
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	}else{
		pageHeight = yScroll;
	}
	return pageHeight;
}