var request; 
/*
key = port_id
file = the file we will load using Ajax
elem = the id of the page element where we wish to load our document
img = the name of our "port" image
*/
function loadContent(key,file,elem,img) {
  var url=file+"?value="+key;
  if (img) {
      getObject(elem).innerHTML = img;  // display a "port" image
  }
// Internet Explorer
  try { 
      request = new ActiveXObject("Msxml2.XMLHTTP");
  } 
  catch(e) { 
      try {
          request = new ActiveXObject("Microsoft.XMLHTTP");
      } 
    catch(oc) { 
       request = null; 
    } 
  }
// Other browsers 
  if (!request && typeof XMLHttpRequest != "undefined") { 
      request = new XMLHttpRequest(); 
  } 
  if (request != null) {
    request.onreadystatechange=function(){
      if(request.readyState!=4)return;
      if(request.status==200){
          getObject(elem).innerHTML = request.responseText  // display our content
      }
    }
    request.open("GET", url, true); 
    request.send(null); 
  } 
} 
// browser compatibility
function getObject(name) { 
  var ns4 = (document.layers) ? true : false; 
  var w3c = (document.getElementById) ? true : false; 
  var ie4 = (document.all) ? true : false; 

  if (ns4) return eval('document.' + name); 
  if (w3c) return document.getElementById(name); 
  if (ie4) return eval('document.all.' + name); 
  return false; 
}