function getMessages(){
  var gotResponse = function(respv){ 
	if(respv.responseText!=undefined && respv.responseText!=''){ 
		document.getElementById("messages").innerHTML = respv.responseText;
	}
    setTimeout('getMessages()',1800000);
  }; 
  var  url='Messages.php';
  if(extParam!=undefined)
	  url+='?'+extParam;
  var param='';
  var callback = { success: gotResponse, failure: false };
  fum.util.Connect.asyncRequest('GET', url, callback, param);               
}
setTimeout('getMessages()',1800000);
getMessages();