ie的大问题，关于document。getElementById和getElementsByName

<script type="text/javascript" language="javascript">

function validRegister(theform){
var username = theform.username.value;
var password1 = theform.password1.value;
var password2 = theform.password2.value;
var email = theform.password2.value;
if(username == ""){
alert("用户名不能为空！");
return false;
}
if(password1 == ""){
alert("密码不能为空！");
return false;
}
if(password2 != password1){
alert("两个密码不相等！");
return false;
}
return true;
}

var XMLHttpReq = false;

function createXMLHttpRequest()
{
if(window.XMLHttpRequest)
{
XMLHttpReq = new XMLHttpRequest();
}
else
{
if(window.ActiveXObject)
{
try{
XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
try{
XMLHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){}
}
}
}

}


function send(url){
createXMLHttpRequest();
XMLHttpReq.open("GET",url,true);

XMLHttpReq.send(null);
XMLHttpReq.onreadystatechange=parse;
}


function parse(){
if(XMLHttpReq.readyState == 4){
if(XMLHttpReq.status == 200){
var res = XMLHttpReq.responseXML.getElementsByTagName("content")[0].firstChild.data;

if(res == "ok"){
document.getElementsByName("status").innerHTML="该用户名可以使用!";

}else{
document.getElementsByName("status").innerHTML=res;
window.alert(res);
}
}else{
window.alert("所请求的页面有异常！");
}
}
}


function checkUsername(){
var username = document.getElementById("username").value;

if(username == ""){
alert("请输入用户名");
return false;
}else{
send('action/checkUsername.jsp?username='+username);
}
}

</script>

注意到蓝色的代码getElementsByName如果改成getElementById则IE里面有可能出错

关于调试时可以尝试着改变getElementById和getElementsByName,互换一下有可能错误就搞定了