Find the position of an element with JavaScript

var util = {
 
	// findPos() by quirksmode.org
	// Finds the absolute position of an element on a page
	findPos: function(obj) {
		var curleft = curtop = 0;
		if (obj.offsetParent) {	
			do {
				curleft += obj.offsetLeft;
				curtop += obj.offsetTop;	
			} while (obj = obj.offsetParent);
		}
		return [curleft,curtop];
	},
 
	// getPageScroll() by quirksmode.org
	// Finds the scroll position of a page
	getPageScroll: function() {
		var xScroll, yScroll;
		if (self.pageYOffset) {
			yScroll = self.pageYOffset;
			xScroll = self.pageXOffset;
		} else if (document.documentElement && document.documentElement.scrollTop) {
			yScroll = document.documentElement.scrollTop;
			xScroll = document.documentElement.scrollLeft;
		} else if (document.body) {// all other Explorers
			yScroll = document.body.scrollTop;
			xScroll = document.body.scrollLeft;
		}
		return [xScroll,yScroll]
	},
 
	// Finds the position of an element relative to the viewport.
	findPosRelativeToViewport: function(obj) {
		var objPos = this.findPos(obj)
		var scroll = this.getPageScroll()
		return [ objPos[0]-scroll[0], objPos[1]-scroll[1] ]
	}
 
}