Excel VBA - Selecting multiple sheets

Issue

I have a certain VBA code that I use for group/ungroup on protected sheet. It works just fine but only on one sheet. How can I modify it to work on two?

Private Sub Workbook_open() 
With Sheet1 
.Protect Password:="secret", userinterfaceonly:=True 
.EnableOutlining = True 
End With 
End Sub 

I don't know how to add more than one sheet. Can somebody help me?

Solution

Try this:

Private Sub Workbook_open() 
With sheets("Sheet1 name") 
.Protect Password:="secret", userinterfaceonly:=True 
.EnableOutlining = True 
End With 
With sheets("Sheet2 name") 
.Protect Password:="secret", userinterfaceonly:=True 
.EnableOutlining = True 
End With 
End Sub

Note

Thanks to Excelguru for this tip on the forum.