JavaScript截取URL參數

var queryString = location.href.substring(location.href.indexOf("?")+1);    //獲得URL傳遞的參數
　　    var parameters = queryString.split("&");                                    //以&分割截取多個參數
        var pos, paraName,paraValue,paraRan,paraUrl;
        for(var i=0; i<parameters.length; i++)
        {
                                                                                    // 獲取等號位置
            pos = parameters[i].indexOf('=');                                       //獲得每個參數對的'='下標
            if(pos == -1)                                                           //如果沒有參數跳出本次循環
            {
                PutCollectSwf();                                                    //默認的首頁統計圖
                continue;
            }
            else                                                                    // 獲取id、密鑰種子 和 url路徑文件名
            {
                paraName = parameters[i].substring(0, pos);
                                                                                    // 參數名必須是id
                if(paraName == "id")
                {
                   paraValue = parameters[i].substring(pos + 1);                    //截取字符串獲得id
                }
                                                                                    //第二個參數必須是ran
                else if(paraName=="ran")
                {
                    paraRan=parameters[i].substring(pos + 1);                       //截取字符串獲得密鑰
                }
                                                                                   //第三個參數必須是url
                else if(paraName=="url")
                {
                    paraUrl=parameters[i].substring(pos + 1);                       //截取字符串獲得URL
                }
               
            }
           
        }