自定义javascript的clone方法
在网上找到的clone方法代码：
方法一：定义一个clone方法来实现。

Object.prototype.Clone = function(){    var objClone;    if ( this.constructor == Object ) objClone = new this.constructor();    else objClone = new this.constructor(this.valueOf());    for ( var key in this )     {        if ( objClone[key] != this[key] )         {            if ( typeof(this[key]) == 'object' )             {                 objClone[key] = this[key].Clone();             }            else             {                 objClone[key] = this[key];             }         }     }     objClone.toString = this.toString;     objClone.valueOf = this.valueOf;    return objClone;}