Problems programmatically deleteing exchange 2003 mailbox

Dim user As DirectoryServices.DirectoryEntry
                    Dim mailbox As CDOEXM.IMailboxStore
                    Dim search As New DirectoryServices.DirectorySearcher(LDAPPath)
                    search.Filter = "(SAMAccountName=" + strSAMAccountName + ")"
                    Dim result As DirectoryServices.SearchResult = search.FindOne()
                    user = result.GetDirectoryEntry()
                    mailbox = DirectCast(user.NativeObject, CDOEXM.IMailboxStore)
                    mailbox.DeleteMailbox()
                    user.CommitChanges()
                    user.Close()