diff -r 431dde3c5fbe -r 84a541c6e093 application/main.c
--- a/application/main.c	Tue Mar 25 20:25:09 2014 +0100
+++ b/application/main.c	Wed Mar 26 15:53:43 2014 +0100
@@ -82,11 +82,13 @@
 void action_undo(UiEvent *event, void *data) {
     printf("undo\n");
     TestWindowData *wd = event->window;
-    //ui_text_undo(&wd->text);
+    ui_text_undo(&wd->text);
 }
 
 void action_redo(UiEvent *event, void *data) {
     printf("redo\n");
+    TestWindowData *wd = event->window;
+    ui_text_redo(&wd->text);
 }
 
 
@@ -101,7 +103,7 @@
     ui_menuitem("Dokument 1", action_doc1, NULL);
     ui_menuitem("Dokument 2", action_doc2, NULL);
     ui_menuseparator();
-    //ui_checkitem_nv("Check", "check1");
+    ui_checkitem_nv("Check", "check1");
     ui_menuitem("Close", action_close, NULL);
     
     
@@ -123,7 +125,7 @@
     
     printf("create window\n");
     UiObject *window = ui_window("Mod0", NULL);
-    TestWindowData *wdata = malloc(sizeof(TestWindowData));
+    TestWindowData *wdata = calloc(1, sizeof(TestWindowData));
     window->window = wdata;
     
     TestDocument *doc1 = ui_document_new(sizeof(TestDocument));