function checkEmail(myEmail) {
// myEmail      : e-mail address
// RETURN VALUE : true on valid e-mail, false otherwise

  // regular expression source: http://www.hexillion.com/samples/
  // Matches a limited version of the RFC 2822 addr-spec form.
  if (!(/^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/.test(myEmail))) {
    return false;
  }

  return true;
}