/*** Quickie e-mail validation (taken from Wikibooks) ***/
function isValidEmail(str) {
  // These comments use the following terms from RFC2822:
  // local-part, domain, domain-literal and dot-atom.
  // Does the address contain a local-part followed an @ followed by a domain?
  // Note the use of lastIndexOf to find the last @ in the address
  // since a valid email address may have a quoted @ in the local-part.
  // Does the domain name have at least two parts, i.e. at least one dot,
  // after the @? If not, is it a domain-literal?
  // This will accept some invalid email addresses
  // BUT it doesn't reject valid ones. 
  var atSym = str.lastIndexOf("@");
  if (atSym < 1) { return false; } // no local-part
  if (atSym == str.length - 1) { return false; } // no domain
  if (atSym > 64) { return false; } // there may only be 64 octets in the local-part
  if (str.length - atSym > 255) { return false; } // there may only be 255 octets in the domain

  // Is the domain plausible?
  var lastDot = str.lastIndexOf(".");
  // Check if it is a dot-atom such as example.com
  if (lastDot > atSym + 1 && lastDot < str.length - 1) { return true; }
  //  Check if could be a domain-literal.
  if (str.charAt(atSym + 1) == '[' &&  str.charAt(str.length - 1) == ']') { return true; }
  return false;
}

/*** Ajax stuff ***/
function makeXMLHttpRequest()
{
  try
  {
    // Works for all Ajax-supporting browsers except MSIE5/6
    return new XMLHttpRequest();
  }
  catch(e)
  {
    // No XMLHttpRequest; maybe this is MSIE5/6?
    try
    {
      return new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        return new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        // No Ajax
        return null;
      }
    }
  }
}

function removeElementById(id)
{
  var elem = document.getElementById(id);
  elem.parent.removeChild(elem);
}