js对象序列化成json数据

 //JS对象
         var UserObj =
         {
           userid:"",
           pword:"",
           username:"",
           position:""
         }
         
        
         function updateUser()
         {  
            //给JS对象赋值
            UserObj.userid = document.getElementsByName("userid")[0].value;
            UserObj.pword= document.getElementsByName("pword")[0].value;
            UserObj.username = document.getElementsByName("username1")[0].value;
            UserObj.position = document.getElementsByName("position")[0].value;
            var objStr = Serialize(UserObj);  // js对象转化成json数据格式
            postXmlHttp("./UpdateUserServlet.do","updateCallback(resultValue)","loadingUpdate()","jsonDate="+objStr);
            //ajax 提交
         }

function Serialize(obj){
    switch(obj.constructor){
        case Object:
            var str = "{";
            for(var o in obj){
                str += o + ":" + Serialize(obj[o]) +",";
            }
            if(str.substr(str.length-1) == ",")
                str = str.substr(0,str.length -1);
            return str + "}";
            break;
        case Array:            
            var str = "[";
            for(var o in obj){
                str += Serialize(obj[o]) +",";
            }
            if(str.substr(str.length-1) == ",")
                str = str.substr(0,str.length -1);
            return str + "]";
            break;
        case Boolean:
            return "\"" + obj.toString() + "\"";
            break;
        case Date:
            return "\"" + obj.toString() + "\"";
            break;
        case Function:
            break;
        case Number:
            return "\"" + obj.toString() + "\"";
            break; 
        case String:
            return "\"" + obj.toString() + "\"";
            break;    
    }
}