Function.prototype.delay =  function(n, thisObj, args) {
    var me = this;
    args = args instanceof Array ? args : [];
    var f = function() {
        me.apply(thisObj || window, args);
    };
    window.setTimeout(f, n);
}
//示例
function f() {
    alert("hi");
}
alert("两秒之后弹出");
f.delay(2000);