[trigon]

Understand i right, that for my problem i only modify this codes:

// Add or remove user from secondary usergroups
// according to radio button choice in user's profile
// (Choice of one of several forums)

  global $vbulletin;

// Enter values in the strings below for your forum
  // custom field containing your radio button
     $field = 'fieldX'
  // membergroup number associated with FIRST radio button choice 
     $mg[0] = 'XX';                     
  // membergroup number associated with SECOND radio button choice 
     $mg[1] = 'YY'; 
  // add additional radio button choices as needed 
                         
// Derive additional needed variables
  $userid = ($vbulletin->userinfo['userid']);                           // userid of user
  $mgarr = explode(',' , (''.$vbulletin->userinfo['membergroupids']));  // current membergroups as array

// Do the work  
  foreach ($mg as $value) 
  {
    $iii = 0
    {
      if ($field == pow(2,$iii))
      {
        InGroup($mgarr, $mg[$iii], $userid);
      } 
      else
      {
        OutGroup($mgarr, $mg[$iii], $userid);      
      } 
      $iii++ 
    }
  }