glaswegian, thanku for ur reply,

I hv solved my solution like this...

I hv created two toolbar icon namely "Lock file" and "Unlock file"...

[VBA]

Sub LockFile()
'
ActiveWorkbook.Password = "123"
ActiveWorkbook.WritePassword = "123"
End Sub

Sub UnlockFile()
'
ActiveWorkbook.Password = ""
ActiveWorkbook.WritePassword = ""
End Sub

[/VBA]