不知道是否可行，但姑且google之。 查看到相关的stack overflow(堆栈溢出）帖子：http://stackoverflow.com/questions/1659219/add-to-a-javascript-function 代码拷贝如下：
var originalFn = addToMe;addToMe =function(){ originalFn();// call the original function// other stuff}; addToMe =function(){ originalFn.apply(this, arguments);// preserve the arguments// other stuff}; addToMe =(function(originalFn){returnfunction(){ originalFn.apply(originalFn, arguments);// call the original function// other stuff};})(addToMe);// pass the reference of the original function 时间太晚，只试了一下第一种最简单的无参数的复写： <html>
<head>
<title>test</title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$(":input[type='hidden']").bind("propertychange",function(){
alert($(this).val())
});
});
function addRow0(){
alert("simple ");
}
</script>
</head>
<body>
<form>
<input id="hf" type="hidden" value="" />
<input type="button" value="test" onclick="$('#hf').val('fire')" />
<input type="button" value="add hidden field" onclick="" />
<input type="button" value="cache that" onclick="addRow0()" />
</form>
</body>
<script type="text/javascript">
function addHidden(){
$("body").after("<input type='hidden' id='hf1' />");
}
var originalFn = addRow0;
addRow0 = function () {
originalFn();
alert(" is the best");
}
</script>
</html>
小伙伴们，有需要可以拿走玩一下。