Auto hide & protect worksheets before closing

Hi folks,

I wrote the following code to hide & password protect an excel sheet :

Sub Hideconfidential()
Worksheets("confidential").Visible = xlSheetVeryHidden
End Sub
Sub UnHideconfidential()
rspn = InputBox("Enter Password")
If rspn <> "Pw" Then Exit Sub
Worksheets("confidential").Visible = xlSheetVisible
End Sub

How could I alter it so that it hides and protects this sheet automatically before closing the workbook ?

Thank you!