add_filter('simplemodal_login_form', 'mytheme_login_form');
function mytheme_login_form($form) {
	$users_can_register = get_option('users_can_register') ? true : false;
	$options = get_option('simplemodal_login_options');

	$output = sprintf('
<form name="loginform" id="loginform" action="%s" method="post">
	<div class="title">%s</div>
	<div class="simplemodal-login-fields">
	<p>
		<label>%s<br />
		<input type="text" name="log" class="user_login input" value="" size="20" tabindex="10" /></label>
	</p>
	<p>
		<label>%s<br />
		<input type="password" name="pwd" class="user_pass input" value="" size="20" tabindex="20" /></label>
	</p>',
		site_url('wp-login.php', 'login_post'),
		__('Login', 'simplemodal-login'),
		__('Username', 'simplemodal-login'),
		__('Password', 'simplemodal-login')
	);

	ob_start();
	do_action('login_form');
	$output .= ob_get_clean();

	$output .= sprintf('
	<p class="forgetmenot"><label><input name="rememberme" type="checkbox" id="rememberme" class="rememberme" value="forever" tabindex="90" />%s</label></p>
	<p class="submit">
		<input type="submit" name="wp-submit" value="%s" tabindex="100" />
		<input type="button" class="simplemodal-close" value="%s" tabindex="101" />
		<input type="hidden" name="testcookie" value="1" />
	</p>
	<p class="nav">',
		__('Remember Me', 'simplemodal-login'),
		__('Log In', 'simplemodal-login'),
		__('Cancel', 'simplemodal-login')
	);

	if ($users_can_register && $options['registration']) {
		$output .= sprintf('<a class="simplemodal-register" href="%s">%s</a>', 
			site_url('wp-login.php?action=register', 'login'), 
			__('Register', 'simplemodal-login')
		);
	}

	if (($users_can_register && $options['registration']) && $options['reset']) {
		$output .= ' | ';
	}

	if ($options['reset']) {
		$output .= sprintf('<a class="simplemodal-forgotpw" href="%s" title="%s">%s</a>',
			site_url('wp-login.php?action=lostpassword', 'login'),
			__('Password Lost and Found', 'simplemodal-login'),
			__('Lost your password?', 'simplemodal-login')
		);
	}

	$output .= ' 
	</p>
	</div>
	<div class="simplemodal-login-activity" style="display:none;"></div>
</form>';

	return $output;
}