function check_nick(nick) {
  var nlen = nick.length;
  var ccod;

  var dolar = 36;  
  var zero = 48;
  var nine = 57;
  var Aupr = 65;
  var Zupr = 90;
  var alwr = 97;
  var zlwr = 122;
  var underscore = 95;
    
  for (var i=0; i<nlen; i++) {
    ccod = nick.charCodeAt();
    if ((ccod<zero && ccod!=dolar) || (ccod>nine && ccod<Aupr) || (ccod>Zupr && ccod<alwr && ccod!=underscore) || (ccod>zlwr))
      return false;
  } // next
  return true;
}

function check_email(email) {
  var ok = "1234567890qwertyuiop[]asdfghjklzxcvbnm.@-_QWERTYUIOPASDFGHJKLZXCVBNM";
  var re_one;
  var re_two;
  var elen = email.length;
      
  for (var i=0; i<elen; i++)
    if (ok.indexOf(email.charAt(i))<0)
      return (false);
  
  if (document.images) {
    re_one = /(@.*@)|(\.\.)|(^\.)|(^@)|(@$)|(\.$)|(@\.)/;
    re_two = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
      
    if (!email.match(re_one) && email.match(re_two))
      return (true);		
  } // fi()
  
  return (false);
} // check_email