Block Alt Key And All Combinations With It Except

This supposed to block Alt key and all combinations with it except Alt+F1, Alt+Tab and Alt+Shift. But what I get is: if I press Alt+F1 only, F1 is triggered.


Private Function LowLevelKeyboardProc(ByVal nCode As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long

Static kbdllhs As KBDLLHOOKSTRUCT

If nCode = HC_ACTION Then
Call CopyMemory(kbdllhs, ByVal lParam, Len(kbdllhs))
If CBool(kbdllhs.flags And LLKHF_ALTDOWN) Then
Select Case kbdllhs.vkCode
Case vbKeyF1, VK_LSHIFT, VK_TAB
Case Else
LowLevelKeyboardProc = 1
Exit Function
End Select
End If
End If
LowLevelKeyboardProc = CallNextHookEx(m_hDllKbdHook, nCode, wParam, lParam)
End Function