ajax»Ø·¢ÎÊÌâ.ÇóÖú.... - Web ¿ª·¢ / Ajax

JScript code:
// JScript Îļþ
var http_reques;
var isbool=false;
function User_CheckNull()
{
var Username=document.getElementById("UserName").value; //»ñÈ¡Ç©µ½Óû§Ãû
if(Username.length==0)
{
document.getElementById("showmsgform").innerHTML="Óû§Ãû²»ÄÜΪ¿Õ";
document.getElementById("UserName").focus();
isbool=false;
}
else
{
send_request('CheckUserName.aspx?username='+Username);
}
return isbool;

}
function add_CheckNull()
{
var Txtname=document.getElementById("Txtname").value; //»ñÈ¡µÇ¼ÇµÄÓû§Ãû
var TxtNumber=document.getElementById("TxtNumber").value; //»ñÈ¡µÇ¼ÇµÄÓû§Ãû
if(Txtname.length==0 ||TxtNumber.length==0)
{
alert("ÊäÈë¿ò²»²»ÄÜΪ¿Õ");
return false;
}
}
//Ìá½»²âÊÔ

function send_request(url)
{
//³õʼ»¯,Ö¸¶¨´¦Àíº¯Êý,·¢ËÍÇëÇóµÄº¯Êý
if(window.XMLHttpRequest)
{
//
http_request=new XMLHttpRequest();
if(http_request.overrideMimeType)
{
//ÉèÖÃMiMEÀà±ð
http_request.overrideMimeType('text/xml');
}
}
else if(window.ActiveXObject)
{
//IEä¯ÀÀÆ÷
try
{
ht