function shadow_show(){
	var height = getScrollHeight()+document.body.clientHeight; 
	$('#shadow_layer').css("height", height); 
	$('#shadow_layer').show();
	$('#info_layer').show(); 
	return false; 
}

function shadow_hide() {
	$('#shadow_layer').hide();
	$('#info_layer').hide(); 
	return false;
}

function getScrollHeight(){
   var h = window.pageYOffset ||
           document.body.scrollTop ||
           document.documentElement.scrollTop;
           
   return h ? h : 0;
}