window.onscroll = function() {
	var menuPane = document.getElementById('rgt');
	var topPos = 150;
	if( window.XMLHttpRequest ) { 
		if (document.documentElement.scrollTop > topPos  || self.pageYOffset > topPos) {
			menuPane.style.position = 'fixed';
		} else {
			menuPane.style.position = 'absolute';
		}
	}
}