应用API时，在哪里进行声明呢？

例如：

'API函数声明 Declare Function SetWindowPos Lib "user32" ( ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long '常量声明 Private Const SWP_NOSIZE = &H1 Private Const SWP_NOMOVE = &H2 Private Const HWND_TOPMOST = -1 Private Const HWND_NOTOPMOST = -2 这些不能写在某个窗体内，请问应该写在哪里？