Проблем под IE с един Ajax код

[cold_zero]

Здравейте, кода си бачка под Opera, Mozilla, Chrome, но под IE неще и неще изписва ми - Object doesn't support this property or method

<center>
<input id="cid" value="<?echo"$cid";?>" type="hidden"><input id="user" value="<?echo"$user";?>" type="hidden">
<input id="chatmsg" class="input" type="text" onkeyup="keyup(event.keyCode);" style="width:80%">
<input type="button" class="button" value="<?echo"$lang[436]";?>" onclick="submit_msg();" style="cursor:pointer;border:1px solid gray;">
</center>
<script type="text/javascript">
          chatmsg.focus()
		  
          var xmlhttp = false;
          var xmlhttp2 = false;

      /* Request for Writing the Message */
      function ajax_write(url){
          if(window.XMLHttpRequest){
              xmlhttp2=new XMLHttpRequest();
              if(xmlhttp2.overrideMimeType){
                  xmlhttp2.overrideMimeType('text/xml');
              }
          } else if(window.ActiveXObject){
              try{
                  xmlhttp2=new ActiveXObject("Msxml2.XMLHTTP");
              } catch(e) {
                  try{
                      xmlhttp2=new ActiveXObject("Microsoft.XMLHTTP");
                  } catch(e){
                  }
              }
          }

          if(!xmlhttp2) {
              alert('Giving up :( Cannot create an XMLHTTP instance');
              return false;
          }

          xmlhttp2.open('GET',url,true);
          xmlhttp2.send(null);
      }

      function submit_msg(){
          msg = document.getElementById("chatmsg").value;
	      cid = document.getElementById("cid").value;
	      user = document.getElementById("user").value;
          document.getElementById("chatmsg").value = "";
          ajax_write("w.php?m=" + msg + "&cid=" + cid + "&u=" + user);
      }

      function keyup(arg1) {
          if (arg1 == 13) submit_msg();
      }
      </script>

 

[cold_zero]

Никой ли незнае ;(