This is modified code to work with mootools to use variables in the sticky element code and give flexibility to the selector being targeted.

sticky-element

// Scrolling sidebar for your website
// Downloaded from Marcofolio.net
// Read the full article: http://www.marcofolio.net/webdesign/create_a_sticky_sidebar_or_box.html
// This has a mootools.js dependency
// Modified by Chris Carvey Eyetrackshop, Inc.

window.onscroll = function()
{ 
  ///////////// Variables ///////////////
  //Change selector and these numbers....
  
	//Insert target selector
  var targetID = 'content';

	//Insert left position
  var leftPos = 767;

  //Insert top position (start)
  var topPos = 476;

  //Insert top position (when sticky fires)
  var topPosSticky = 476;

///////////// End Variables ///////////////

  //Leave the rest of this alone....

	if ( window.XMLHttpRequest ) {
		if (document.documentElement.scrollTop > topPos || self.pageYOffset > topPos) {
			$(targetID).style.position = 'fixed';
			$(targetID).style.top = topPos + 'px';
			$(targetID).style.left = leftPos + 'px';
		} else if (document.documentElement.scrollTop < topPos || self.pageYOffset < topPos) {
			$(targetID).style.position = 'absolute';
			$(targetID).style.top = topPosSticky + 'px';
			$(targetID).style.left = leftPos + 'px';
		}
	}
}