Form submition don't work
drupal_get_form has to be called to render a correct form.

Alter the hook_menu definition to this:

function tournament_menu() {
    $items['tournament/newteam'] = array(
        'title' =&gt; t('Créer une nouvelle équipe'),
        'page callback' =&gt; 'drupal_get_form',
        'page arguments' =&gt; array('form_newteam')
        'access callback' =&gt; TRUE,
        'file' =&gt; 'form_tournament.inc',
    );
}