<form method="post" action="/{path_to_your_forum}/login.php">
Username:<input class="post" type="text" name="username" size="10" /><br />
Password:<input class="post" type="password" name="password" size="10" maxlength="32" /><br />
Log me on automatically each visit<input class="text" type="checkbox" name="autologin" /><br />
<input type="submit" class="mainoption" name="login" value="Log in" />
</form>