var xmlHttp

function loadClasses( studioId )
{ 
  xmlHttp = getXmlHttpObject()

  if ( xmlHttp == null )
  {
    alert ("Browser does not support HTTP Request");
    return;
  } 
  var url = "/schedules/upcoming_classes.php";
  url = url + "?ajax=true&studioId=" + studioId;
  xmlHttp.onreadystatechange = stateChanged;
  xmlHttp.open("GET",url,true);
  xmlHttp.send(null);
}

function stateChanged() 
{ 
  if ( xmlHttp.readyState == 4 || xmlHttp.readyState == "complete" )
  {
    document.getElementById("classScheduleData").innerHTML = xmlHttp.responseText;
  }
} 

function getXmlHttpObject()
{ 
  var objXMLHttp = null
  if ( window.XMLHttpRequest )
  {
    objXMLHttp=new XMLHttpRequest()
  }
  else if ( window.ActiveXObject )
  {
    objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP")
  }
  return objXMLHttp
}