window.onscroll = moveMenuBar;
document.onscroll = moveMenuBar;


function findScrollTop() {
	var top = null;
	if (window.pageYOffset)
	{
		top = window.pageYOffset;
	}
	else
	{
		top = document.body.scrollTop? document.body.scrollTop: document.documentElement.scrollTop;
	}	
	return top;
}

	function moveMenuBar() {
		var object=document.getElementById('menuBar');
		var y = findScrollTop();	
		object.style.display = 'none';
		object.style.top = (20 + y) + 'px';	
		object.style.display = 'block';
	}