osd on button fullscreen

backup/main.lfm

@@ -6066,6 +6066,7 @@ object GUIForm: TGUIForm
       end
       object miDisableScanlines: TMenuItem
         Caption = 'Disable Scanlines'
+        OnClick = miDisableScanlinesClick
       end
       object N4: TMenuItem
         Caption = '-'

backup/main.pas

@@ -411,6 +411,7 @@ type
     procedure miDHRMonoRasterClick(Sender: TObject);
     procedure miDHRMonoVoxelsClick(Sender: TObject);
     procedure miDisableFocusStealingClick(Sender: TObject);
+    procedure miDisableScanlinesClick(Sender: TObject);
     procedure miDisk1WPToggleClick(Sender: TObject);
     procedure miDisk2WPToggleClick(Sender: TObject);
     procedure miDiskMenuBlankClick(Sender: TObject);
@@ -1088,6 +1089,15 @@ begin
   disableFocusStealing:=(not disableFocusStealing);
 end;
 
+procedure TGUIForm.miDisableScanlinesClick(Sender: TObject);
+begin
+  miDisableScanlines.Checked := (not miDisableScanlines.Checked);
+  if miDisableScanlines.Checked then
+     UpdateConfig('video/init.video.scanlinedisable', '1', true)
+  else
+     UpdateConfig('video/init.video.scanlinedisable', '0', true);
+end;
+
 procedure TGUIForm.miDisk1WPToggleClick(Sender: TObject);
 begin
   SimpleGet( baseUrl + '/api/control/hardware/disk/wp/0/toggle' );

main.pas

@@ -1924,6 +1924,7 @@ procedure TGUIForm.tbFullscreenClick(Sender: TObject);
 begin
   UpdateConfig('video/current.fullscreen', '1', false);
   isFS := true;
+  SendOSDMessage('Alt/Option Enter to leave fullscreen');
 end;
 
 procedure TGUIForm.UpdateAllCaps;