Private Sub Workbook_Open()
Dim user As Variant, struser As String
Application.ScreenUpdating = False
struser = Application.UserName
L1:
user = Application.InputBox("May i know your name Pls!!!") ', "Login User", , , , , , Type:=2)
Select Case user
Case False
ThisWorkbook.Close False
Case ""
MsgBox "You must click Cancel to exit.", 48, "Nothing."
GoTo L1
End Select
End Sub