Error Using SqlServer SMO.

Hi,
I want to transfer database objects from One Database to other including all keys that exists between tables using SqlServer SMO .I had tried with MSDN Code but i am facing with some error i.e.,


ERROR : errorCode=-1073548784 description=Executing the query "DROP USER [UserName]
" failed with the following error: "Cannot drop the user 'UserName', because it does not exist or you do not have permission.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.
helpFile= helpContext=0 idofInterfaceWithError={8BDFE893-E9D8-4D23-9739-DA807BCDC2AC}

I tried with MSDN Code:

'Reference the AdventureWorks database
Dim db As Database
db = srv.Databases("AdventureWorks")
'Create a new database that is to be destination database.
Dim dbCopy As Database
dbCopy = New Database(srv, "AdventureWorksCopy")
dbCopy.Create()
'Define a Transfer object and set the required options and properties.
Dim xfr As Transfer
xfr = New Transfer(db)
xfr.CopyAllTables = True
xfr.Options.WithDependencies = True
xfr.Options.ContinueScriptingOnError = True
xfr.DestinationDatabase = "AdventureWorksCopy"
xfr.DestinationServer = srv.Name
xfr.DestinationLoginSecure = True
xfr.CopySchema = True
'Script the transfer. Alternatively perform immediate data transfer with TransferData method.
xfr.ScriptTransfer() or xfr.TransferData()

Thanks In Advance,
Balaji.