/**
* John Resig method
http://ejohn.org/projects/flexible-javascript-events/
addEvent( obj, 'mouseover', function(){ alert('hello!'); } );
*/
function addEvent( obj, type, fn )
{ 
   if (obj.addEventListener) {
      obj.addEventListener( type, fn, false );
   } else if (obj.attachEvent) {
      obj["e"+type+fn] = fn;
      obj[type+fn] = function() { obj["e"+type+fn]( window.event ); }
      obj.attachEvent( "on"+type, obj[type+fn] );
   }
}

function removeEvent( obj, type, fn )
{
   if (obj.removeEventListener) {
      obj.removeEventListener( type, fn, false );
   } else if (obj.detachEvent) {
      obj.detachEvent( "on"+type, obj[type+fn] );
      obj[type+fn] = null;
      obj["e"+type+fn] = null;
   }
}