$ta = "<B>CHAT</B></a> (<strong><a href=\"javascript:show_hide(ShowHide101)\">".$nb_users."</a></strong>)<div id='ShowHide101'>";

foreach($users as $u)

{

$ta .= "  ~ ".$u."<br>";

}

$ta .= "</div><script>show_hide(ShowHide101)</script><a>";