var dom = new Object();
dom.event = new Object();

dom.event.addEventListener = function(elm, type, func, useCapture){
  if(! elm){ return falser; }
  if(! useCapture){ useCapture = false; }
  if(elm.addEventListener){
     elm.addEventListener(type,func,false); 
  } else if(elm.attachEvent){ 
     elm.attachEvent('on'+type,func); 
  } else { 
    return false; 
  }
  return true;
};

dom.event.removeEventListener = function(elm, type, func, useCapture){
  if(! elm){ return falser; }
  if(! useCapture){ useCapture = false; }
  if(elm.removeEventListener){
     box.removeEventListener(type,func,false); 
  } else if(elm.detachEvent){ 
     elm.detachEvent('on'+type,func); 
  } else { 
    return false; 
  }
  return true;
};