在IE中使用AJAX时不加载CSS

Question

I am trying to load a php file using ajax and all is working perfectly in chrome. but when using IE, the CSS in the php file is not working.

here are my codes for the AJAX:

function showUser() {
   var skill = document.getElementById("skill").value
   if ( skill == "" ) {
      document.getElementById("txtHint").innerHTML = "";
      return;
   }
   if ( window.XMLHttpRequest ) { // code for IE7+, Firefox, Chrome, Opera, Safari
      xmlhttp=new XMLHttpRequest();
   } else { // code for IE6, IE5
      xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
   }
   xmlhttp.onreadystatechange = function() {
      if ( xmlhttp.readyState == 4 && xmlhttp.status == 200 ) {
          document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
   }
}
xmlhttp.open("GET", "getuser.php?q=" + skill, true);
xmlhttp.send();
}

getuser.php has css codes that works and echos <img src = 'pics.jpg' class ='img_div'> so again, it works with chrome but the css did not apply in IE.

Thanks, James