Index: wp-admin/network/themes.php
===================================================================
--- wp-admin/network/themes.php	(revision 17089)
+++ wp-admin/network/themes.php	(working copy)
@@ -35,37 +35,40 @@
 	switch ( $action ) {
 		case 'enable':
 			$allowed_themes[ $_GET['theme'] ] = true;
+			$update = 'enabled';
 			update_site_option( 'allowedthemes', $allowed_themes );
-			wp_redirect( wp_get_referer() ); // @todo add_query_arg for update message
-			exit;			
 			break;
 		case 'disable':
 			unset( $allowed_themes[ $_GET['theme'] ] );
+			$update = 'disabled';
 			update_site_option( 'allowedthemes', $allowed_themes );
-			wp_redirect( wp_get_referer() ); // @todo add_query_arg for update message
-			exit;
 			break;
 		case 'enable-selected':
 			$themes = isset( $_POST['checked'] ) ? (array) $_POST['checked'] : array();
-			if ( empty($themes) ) {
-				wp_redirect( wp_get_referer() );
-				exit;
-			}						
-			foreach( (array) $themes as $theme )
-				$allowed_themes[ $theme ] = true;
-			update_site_option( 'allowedthemes', $allowed_themes );
+			if ( ! empty($themes) ) {
+				$update = 'enable';
+				foreach( (array) $themes as $theme )
+					$allowed_themes[ $theme ] = true;
+				update_site_option( 'allowedthemes', $allowed_themes );
+			} else {
+				$update = 'error';
+			}
 			break;
 		case 'disable-selected':
 			$themes = isset( $_POST['checked'] ) ? (array) $_POST['checked'] : array();
-			if ( empty($themes) ) {
-				wp_redirect( wp_get_referer() );
-				exit;
-			}						
-			foreach( (array) $themes as $theme )
-				unset( $allowed_themes[ $theme ] );
-			update_site_option( 'allowedthemes', $allowed_themes );
+			if ( ! empty($themes) ) {
+				$update = 'disable';
+				foreach( (array) $themes as $theme )
+					unset( $allowed_themes[ $theme ] );
+				update_site_option( 'allowedthemes', $allowed_themes );
+			} else {
+				$update = 'error';
+			}
 			break;
 	}
+
+	wp_redirect( add_query_arg( 'update', $update, wp_get_referer() ) );
+	exit;	
 }
 
 $wp_list_table->prepare_items();
@@ -96,6 +99,22 @@
 	printf( '<span class="subtitle">' . __('Search results for &#8220;%s&#8221;') . '</span>', esc_html( $s ) ); ?> 
 </h2>
 
+<?php
+if ( isset( $_GET['update'] ) ) {
+	switch ( $_GET['update'] ) {
+	case 'enabled':
+		echo '<div id="message" class="updated"><p>' . __( 'Theme enabled.' ) . '</p></div>';
+		break;
+	case 'disabled':
+		echo '<div id="message" class="updated"><p>' . __( 'Theme disabled.' ) . '</p></div>';
+		break;
+	case 'error':
+		echo '<div id="message" class="error"><p>' . __( 'No theme selected.' ) . '</p></div>';
+		break;
+	}
+}
+?>
+
 <form method="get" action="">
 <?php $wp_list_table->search_box( __( 'Search Installed Themes' ), 'theme' ); ?>
 </form>