sub.gotoAndStop(this._name);大家帮我看看这个_name是什么意思

  sub.gotoAndStop(this._name);
myURL = [["[url]http://lfg520.xinwen365.met[/url]", "category1.htm", "category1.htm", "category1.htm"], ["category2.htm", "category2.htm", "category2.htm"], ["category3.htm", "category3.htm", "category3.htm", "category3.htm"], ["category4.htm", "category4.htm"]];
for (i=1; i<=myURL[this._name-1].length; i++) {
   sub[i].onRollOver = function() {
       _global.over = this._parent._parent._name;
   };
   sub[i].onRollOut = sub[i].onDragOut=function () {
       _global.over = active;
   };
   sub[i].onRelease = function() {
       getURL(myURL[this._parent._parent._name-1][this._name-1], "_self");
   };
}
帮我解释下这段代码特别是那循环语句.谢谢了 [s:18]

_name是影片剪辑的实例名称