Kevin Phillips

I’ve created a small plugin that you are free to use that validates fields on a custom post type, replaces the standard admin notice with a custom admin notice, no javascript required

add_action('save_post', 'album_save_post', 10, 2);

function album_save_post( $album_id, $album ) {

	if( defined('DOING_AUTOSAVE') && DOING_AUTOSAVE || $album->post_type != 'music_album') return;

	// echo '<pre>';
	// print_r($album);
	// echo '</pre>';
	// die();

	$errors = array();

	// Validation filters
	$title = $album->post_title;
	if ( ! $title ) {
		$errors['title'] = "The title is required";
	}

	// if we have errors lets setup some messages
	if (! empty($errors)) {

		// we must remove this action or it will loop for ever
		remove_action('save_post', 'album_save_post');

		// save the errors as option
		update_option('album_errors', $errors);

		// Change post from published to draft
		$album->post_status = 'draft';

		// update the post
		wp_update_post( $album );

		// we must add back this action
		add_action('save_post', 'album_save_post');

		// admin_notice is create by a $_GET['message'] with a number that wordpress uses to
		// display the admin message so we will add a filter for replacing default admin message with a redirect
		add_filter( 'redirect_post_location', 'album_post_redirect_filter' );
	}
}

function album_post_redirect_filter( $location ) {
	// remove $_GET['message']
	$location = remove_query_arg( 'message', $location );

	// add our new query sting
	$location = add_query_arg( 'album', 'error', $location );

	// return the location query string
	return $location;
}

// Add new admin message
add_action( 'admin_notices', 'album_post_error_admin_message' );

function album_post_error_admin_message() {
	if ( isset( $_GET['album'] ) && $_GET['album'] == 'error' ) {
		// lets get the errors from the option album_errors
		$errors = get_option('album_errors');

		// now delete the option album errors
		delete_option('album_errors');

		$display = '<div id="notice" class="error"><ul>';

		// Because we are storing as an array we should loop through them
		foreach ( $errors as $error ) {
			$display .= '<li>' . $error . '</li>';
		}

		$display .= '</ul></div>';

		// finally echo out our display
		echo $display;

		// add some jQuery
		?>
		<script>
		jQuery(function($) {
			$("#title").css({"border": "1px solid red"})
		});
		</script>
		<?php
	}
}

full tutorial here:
http://kevinphillips.co.nz/news/custom-post-type-validation-without-javascript/