function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "external")
     anchor.target = "_blank";
 }
}
window.onload = externalLinks;

function $(id) { return document.getElementById(id); }





function change_content(elem,link)
  {
  var xmlHttp;
  try
    {
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
    }
  catch (e)
    {
    // Internet Explorer
    try
      {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
      }
    catch (e)
      {
      try
        {
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
      catch (e)
        {
        alert("Your browser does not support AJAX!");
        return false;
        }
      }
    }
    xmlHttp.onreadystatechange=function()
      {
      if(xmlHttp.readyState==4)
        {
        $(elem).innerHTML=xmlHttp.responseText;
        }
      }
    xmlHttp.open("GET",link,true);
    xmlHttp.send(null);
  }