我创建了一个隐藏框架如下：

var oHiddenFrame = null;
if(oHiddenFrame == null){
oHiddenFrame = document.createElement("iframe");
oHiddenFrame.name = "hiddenFrame";
oHiddenFrame.id = "hiddenFrame";
oHiddenFrame.style.height = "0px";
oHiddenFrame.style.width = "0px";
oHiddenFrame.style.position = "absolute";
oHiddenFrame.style.visbility = "hidden";
document.body.appendChild(oHiddenFrame);
}

然后给页面上的按钮创建了监听函数：

var fnLocation = function(){
frames["hiddenFrame"].location.href = "http://meckmeck.cn";
}

var oButton = document.getElementById("mb_submit");
oButton.addEventListener("click", fnLocation, false);

这样把代码直接写在页面里能正常运行，但是写到GreaseMonkey里运行时就会出现frames.hiddenFrame is undefined错误。