I need my program to put an icon in the system tray area, so i'm using this code:

Public Sub CreateIcon(Control As PictureBox)
Dim Tic As NOTIFYICONDATA
Dim Erg As Variant

Tic.cbSize = Len(Tic)
Tic.hWnd = Control.hWnd
Tic.uID = 1&
Tic.uFlags = NIF_MESSAGE Or NIF_ICON Or NIF_TIP 'NIF_DOALL
Tic.uCallbackMessage = WM_MOUSEMOVE
Tic.hIcon = Control.Picture
Tic.szTip = App.ProductName & AppVersionS & Chr$(0)
Erg = Shell_NotifyIcon(NIM_ADD, Tic)

End Sub

if i start closing my apps pressing Alt+F4, sometime even my VB app get closed (i don't want this happen because it's a security app), how can i avoid this behavior?