function showAlert(alertText) {
  var alertbox = document.getElementById('alertbox');
  alertbox.innerHTML += '<br>' + alertText;
}

var t;
function scrollAlert() {
  var alertbox = document.getElementById('alertbox');
  if (alertbox.scrollTop < getElementHeight(alertbox)) {
    alertbox.scrollTop++;
    t = setTimeout("scrollAlert()", 80);
  } else {
    t = null;
  }
}
function scrollAlertEnd() {
  var alertbox = document.getElementById('alertbox');  
  alertbox.scrollTop = getElementHeight(alertbox);
}

function getElementHeight(element) {
  var height;
  var test1 = element.scrollHeight;
  var test2 = element.offsetHeight
  if (test1 > test2) // all but Explorer Mac
  {
  	height = element.scrollHeight;
  }
  else // Explorer Mac;
       //would also work in Explorer 6 Strict, Mozilla and Safari
  {
  	height = element.offsetHeight;
  }
  return height;
}

function pingUser() {
  ajaxGet(pingComplete, '/ajax_pinguser.aspx');
}
function pingComplete(http_request) {
  if (http_request) {
    if (http_request.readyState == 4) {
      if (http_request.status == 200) {
        if (http_request.responseXML && http_request.responseXML.documentElement)
          processPingXML(http_request.responseXML.documentElement);
      }
      setTimeout("pingUser()", 5000);
    }
  }
}


function processPingXML(documentNode) {

  for (var x=0; x < documentNode.childNodes.length; x++) {
    var node = documentNode.childNodes.item(x);
    var innertext = GetInnerText(node);
    switch (node.nodeName) {
      case 'alert':
        showAlert(innertext);
        break;
    }
  }
  if (t==null)
    scrollAlert()
}
 

function alertFriend(u) {
  var txtAlert = prompt("Type in a short message to send:", "");
  if (txtAlert.length > 0) {
    ajaxGet(null, '/ajax_alert.aspx?u='+u+'&txt='+encodeURIComponent(txtAlert));
  }
}

function typeLoginText(event) {

 var hitReturn=false;
 if (document.all){
  if (event.keyCode == 13){
   hitReturn=true;
  }
 }
 else if (document.getElementById){
  if (event.which == 13){
   hitReturn=true;
  }
 }
 else if(document.layers){
  if(event.which == 13){
   hitReturn=true;
  }
 }
 if (hitReturn) {
  document.loginForm.submit();
  return false;
 }
 else
  return true;
}