index.js
function (oTarget, sEventType, fnHandler) {
  oTarget.listeners = oTarget.listeners || {};
  var listeners = oTarget.listeners[sEventType] = oTarget.listeners[sEventType] || [];
  listeners.push(fnHandler);
  if (!listeners["_handler"]) {
    listeners["_handler"] = function (e) {
      var e = e || window.event;
      for (var i = 0, fn; fn = listeners[i++];) {
        fn.call(oTarget, e)
      }
    }
    oTarget.addEventListener ? oTarget.addEventListener(sEventType, listeners["_handler"], false) : oTarget.attachEvent('on' + sEventType, listeners["_handler"]);
  }
}
function (oTarget, sEventType, fnHandler) {
  oTarget.listeners = oTarget.listeners || {};
  var listeners = oTarget.listeners[sEventType] = oTarget.listeners[sEventType] || [];
  listeners.push(fnHandler);
  if (!listeners["_handler"]) {
    listeners["_handler"] = function (e) {
      var e = e || window.event;
      for (var i = 0, fn; fn = listeners[i++];) {
        fn.call(oTarget, e)
      }
    }
    oTarget.addEventListener ? oTarget.addEventListener(sEventType, listeners["_handler"], false) : oTarget.attachEvent('on' + sEventType, listeners["_handler"]);
  }
}
function ( oTarget , sEventType , fnHandler ) { oTarget . listeners = oTarget . listeners || { } ; var listeners = oTarget . listeners [ sEventType ] = oTarget . listeners [ sEventType ] || [ ] ; listeners . push ( fnHandler ) ; if ( ! listeners [ "_handler" ] ) { listeners [ "_handler" ] = function ( e ) { var e = e || window . event ; for ( var i = 0 , fn ; fn = listeners [ i ++ ] ; ) { fn . call ( oTarget , e ) } } oTarget . addEventListener ? oTarget . addEventListener ( sEventType , listeners [ "_handler" ] , false ) : oTarget . attachEvent ( 'on' + sEventType , listeners [ "_handler" ] ) ; } }
/*添加事件
@param {Object} oTarget 对象
@param {String} sEventType 事件类型
@param {Function} fnHandler 事件方法
/ * 添加事件