无刷新基本龙骨

var READY_STATE_UNINITIALIZED=0;
var READY_STATE_LOADING=1;
var READY_STATE_LOADED=2;
var READY_STATE_INTERACTIVE=3;
var READY_STATE_COMPLETE=4;
var req;
function sendRequest(url,params,HttpMethod){
 if (!HttpMethod){
  HttpMethod="GET";
 }
 req=getXMLHTTPRequest();
 if(req){
  req.onreadystatechange=onReadyStateChange;
  req.open(HttpMethod,url,true);
  req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  req.send(params);
 }
}
function onReadyStateChange(){
 var ready=req.readyState;
 var data=null;
 if (ready==READY_STATE_COMPLETE){
  data=req.responseText;
 }else{
  data="loading...["+ready+"]";
 }
//... do something with the data...
}