VBA Excel 2007 Security warning when closing workbook with Task Manager

[vbexceltuto]

In Excel 2007 I Create file and macro (vba), I protected workbook using password
and to avoid Security warning when closing file through icon red (X) and reopen file and after save my data and indeed, the problem is solved

Steps
1- to avoid Security warning (code problem solved is down )2- Closing file with red icon (X)
3- Reopen file
4- Save my work
5- work fine

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    ThisWorkbook.Unprotect Password:="blabla"    ThisWorkbook.Save    ThisWorkbook.Saved = True
End Sub


Private Sub Workbook_Open()
    ThisWorkbook.Protect Password:="blabla"    ThisWorkbook.Save    ThisWorkbook.Saved = True
End Sub

But window Security warning arise when Closing file with Task manager and next reopen file, code above not working