dom = {};
dom.addEvent=function(el,type,fn){if(el.attachEvent){el['e'+type+fn]=fn;el[type+fn]=function(){el['e'+type+fn](window.event);};el.attachEvent('on'+type,el[type+fn]);}else{el.addEventListener(type,fn,false);}};
dom.removeEvent=function(el,type,fn){if(el.detachEvent){el.detachEvent('on'+type,el[type+fn]);el[type+fn]=null;}else{el.removeEventListener(type,fn,false);}};