function reposition(){
			var el = document.getElementById('reference_navigation_menu');
			
			var ScrollTop = document.body.scrollTop;
			if (ScrollTop == 0)
			{
				if (window.pageYOffset)
					ScrollTop = window.pageYOffset;
				else
					ScrollTop = (document.body.parentElement) ? document.body.parentElement.scrollTop : 0;
			}
			if(ScrollTop < 515)
				el.style.top = 515 - ScrollTop + "px";
			else
				el.style.top = "0px";
		}