ajax to xmlhttp 问题

Question

1.有responseText和responseXml
2.要等xmlHttp對象準備好返回你才能接收結果
比如：
var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    xmlhttp.Open("GET",URL, false);
    try { 
        xmlhttp.send(); 
       var result = xmlhttp.status;}
    catch(e) {return(false);}
  if(result==200) { 
      return(xmlhttp.responseText); 
             }
   delete(xmlhttp)

Answer 1

var url= "xxxx.ashx?sPhone="+xxxx+"&inc="+inc;
 这一行 最好加一个随机数
 防止有缓存 
 var url= "xxxx.ashx?sPhone="+xxxx+"&inc="+inc+"tt="+makeRandChar();function makeRandChar()        {
        
            //创建随机数            var tmpstr = '';
            var chars = "0123456789abcdefghijklmnopqrstuvwxyz";
            var chrlen = chars.length;
            var  len = "16";
            var iRandom ;            do{                iRandom = Math.round(Math.random() * chrlen);                tmpstr += chars.charAt(iRandom);                if( tmpstr.length == len ) break;                }while (tmpstr.length < len)            return tmpstr;        }

Answer 2

function GetRequest()
{
var url = "test.xml";
xmlHttp = GetXMLHttpRequest();
xmlHttp.onreadystatechange = OnReadyStateChange;
xmlHttp.open("GET", url, false);
xmlHttp.send("");
}

function OnReadyStateChange()
{
if(xmlHttp.readyState == 4)
{
    if(xmlHttp.status == 200)
    {
//         var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
//         xmlDoc.loadXML(xmlHttp.responseText);
                var xmlDoc = xmlHttp.responseXML;
        var i = xmlDoc.getElementsByTagName("ad")[0].firstChild.firstChild.nodeValue;
        alert(i);
    }
}
}