一个简单的AJAX请求类

    if (!xmlObj) return false;
    this.method="POST";
    this.url;
    this.async=true;
    this.content="";
    this.callback=function(cbobj) {return;}
    this.send=function() {
        if(!this.method||!this.url||!this.async) return false;
        xmlObj.open (this.method, this.url, this.async);
        if(this.method=="POST") xmlObj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
        xmlObj.onreadystatechange=function() {
            if(xmlObj.readyState==4) {
                if(xmlObj.status==200) {
                    ObjSelf.callback(xmlObj);
                }
            }
        }
        if(this.method=="POST") xmlObj.send(this.content);
        else xmlObj.send(null);
    }
}