[Andreas]

The edited Version looks correct (if there are no missing brackets or whatever)

But you can shorten it

PHP Code:

if ($this->existing['usergroupid'] != 3 AND $this->existing['email'] != $this->fetch_field('email') AND strpos($this->fetch_field('field6'), $this->fetch_field('email')) === false))
{
    $this->setfields['field6'] = true;
    $this->userfield['field6'] = (($this->fetch_field('field6'))  ? $this->fetch_field('field6') . ', ' . $this->fetch_field('email') : $this->fetch_field('email'));
}