AppendMenu and RemoveMenu API?

The following functions can be used to add and remove items to/from the control menu. Can anyone explain to me what are the values and meanings for the:

1. wFlags (in both functions)
2. wIDNewItem

Declare Function RemoveMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long

Declare Function AppendMenu Lib "user32" Alias "AppendMenuA" (ByVal hMenu As Long, ByVal wFlags As Long, ByVal wIDNewItem As Long, ByVal lpNewItem As String) As Long

RetVal = RemoveMenu (hMenu, nPosition, wFlags)
RetVal = AppendMenu (hMenu, wFlags, wIDNewItem, lpNewItem)

Thanks.