function skolerute(date) {
   xmlHttp = GetXmlHttpObject();
   if(xmlHttp == null)
      return;
   xmlHttp.onreadystatechange = function() {
      if(xmlHttp.readyState == 4) {
         document.getElementById('skolerute').innerHTML = xmlHttp.responseText;
      }
   }
   xmlHttp.open('GET', 'includes/skolerute.php?date=' + date, true);
   xmlHttp.send(null);
}

function GetXmlHttpObject() {
   var xmlHttp;
   try {
      xmlHttp = new XMLHttpRequest(); // Firefox, Opera 8.0+, Safari
   } catch(e) {
      try {
         xmlHttp = new ActiveXObject('Msxml2.XMLHTTP'); // Internet Explorer 6.0+
      } catch(e) {
         xmlHttp = new ActiveXObject('Microsoft.XMLHTTP'); // Internet Explorer 5.5+
      }
   }
   return xmlHttp;
}