一个通用的链接类 JPageUrl

/*================================= 链接类 JPageUrl{===================================*/
function JPageUrl(url) {
    this.url = url.toLower();
}

JPageUrl.prototype.add = function(name, value){
    if(this.url.isNullOrEmpty() == true)
        return "";
   
    if(!name.isNullOrEmpty()) {
        var pi = this.url.indexOf(name);
        if(pi != -1) {
            var tempstring = this.url.substr(pi, this.url.length - pi);
            var pj = tempstring.indexOf("&");
            if(pj == -1)
            {
                this.url = this.url.replace(tempstring, name + "=" + this.encode(value));
            }
            else
            {
                var tempstr0 = tempstring.substr(0, pj);
                this.url = this.url.replace(tempstr0, name + "=" + this.encode(value));
            }
        }
        else{
            if (this.url.indexOf("?") != -1)
                this.url += "&" + name + "=" + this.encode(value);
            else
                this.url += "?" + name + "=" + this.encode(value);
        }
    }
}

JPageUrl.prototype.encode = function(value) {
    return encodeURIComponent(value);
}
/*================================= }链接类 JPageUrl ===================================*/