rem: return event.pageX || (event.clientX + 
add: return event.pageX || (event.clientX + 
context:   pointerX: function(event) {    return event.pageX || (event.clientX +       (document.documentElement.scrollLeft || document.body.scrollLeft));  },
meta: 2355	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2355/9867ca01ad65827d23c0bf6cc14d8a64137e927d/prototype.js/clean/tracks/public/javascripts/prototype.js