function trim(s)
{
  while (s.substring(0,1) == ' ') {
    s = s.substring(1,s.length);
  }
  while (s.substring(s.length-1,s.length) == ' ') {
    s = s.substring(0,s.length-1);
  }
  return s;
}

function isValidEmail(s)
{
    return ((s.indexOf('@') >= 1) &&
            (s.indexOf('@') == s.lastIndexOf('@')) &&
            (s.indexOf('@') < s.length - 1) && 
            (s.substring(s.indexOf('@') + 1, s.indexOf('@') + 2) != '.') && 
            (s.lastIndexOf('.') > s.indexOf('@') + 1) &&
            (s.lastIndexOf('.') < s.length - 1))
}