ajax兼容问题,大家帮我看看,我的在ff和opera下不惯用啊,急死人了,是不是js不规范,大家帮我修正下,谢谢.

<!--
var xmlHttp;
function GetNowTime(){
 var date = new Date(); //ÈÕÆÚ¶ÔÏó 
 var now = \"\"; 
 now = date.getFullYear()+\"y\";
 now = now + (date.getMonth()+1)+\"m\";
 now = now + date.getDate()+\"d\"; 
 now = now + date.getHours()+\"h\"; 
 now = now + date.getMinutes()+\"m\"; 
 now = now + date.getSeconds()+\"s\";
 return now;
}
function CleanLoading(){
 document.getElementById('loading').innerHTML = \"\";
}
function createXMLHttpRequest(){
 if (typeof XMLHttpRequest == \"undefined\"){
  var xmlHttpVersions = [ \"MSXML2.XMLHttp.5.0\",\"MSXML2.XMLHttp.4.0\",\"MSXML2.XMLHttp.3.0\",\"MSXML2.XMLHttp\",\"Microsoft.XMLHttp\"];
  for(var i = 0;i < xmlHttpVersions.Length;i++){
   try{
    return new ActiveXObject(xmlHttpVersions[i]);
   }
   catch(oError){
    //there is nothing to do with
   }
  }
  throw new error(\"there whould be no error at all!\");
 }
 else if (window.XMLHttpRequest){
  return new XMLHttpRequest();
 }
}
 
 if (ajax == null && typeof XMLHttpRequest != 'undefined')
 {
  ajax = new XMLHttpRequest();
 }
 
 return ajax;
}
function starRequest(object,VerID){
 var url;
 switch(object){
  case 1: { //Â¥ÅÌÐÅÏ¢,ÏîÄ¿¸Å¿ö
   url = \"/ajax/gaikuang.php?VerID=\"+VerID+\"&time=\"+GetNowTime();//¼ÓÈëʱ¼ä´Á,±ÜÃâä¯ÀÀÆ÷»º´æ
   break;
  }
  case 2: { //Â¥ÅÌÐÅÏ¢,ÏîÄ¿¸Å¿ö
   url = \"/ajax/gaikuang.php?VerID=\"+VerID+\"&time=\"+GetNowTime();
   break;
  }
 }
 xmlHttp = createXMLHttpRequest();
 xmlHttp.onreadystatechange = handleStateChange;
 xmlHttp.open(\"get\",url,true);
  xmlHttp.setRequestHeader(\"Content-Type\", \"application/x-www-form-urlencoded\");
 xmlHttp.send(null);
}
function handleStateChange(){
 document.getElementById('loading').innerHTML = \"<img src='/images/loading3.gif'/>Êý¾Ý¼ÓÔØÖÐ...\";
 if(xmlHttp.readyState == 4){
  if(xmlHttp.status == 200){
   document.getElementById('main').innerHTML = xmlHttp.responseText;
  }
 }
 setTimeout(\"CleanLoading()\",500);
}
-->