Attaching Db Error After Copy

i tried to copy the database manually by using sqldmo
here r my codes:


On Error GoTo CopySQLDB_Err

'Create Objects
Set sql = CreateObject("SQLDMO.SQLServer")
Set db = CreateObject("SQLDMO.Database")

'Connect to the server
sql.Connect strSrv, strLogin, strPwd

'Set the database object
Set db = sql.Databases(strDatabase, "dbo")

'Determine the location of database files, primary and log
strMDFfilePath = db.PrimaryFilePath
strMDFfileName = _
Trim(db.FileGroups.Item(1).DBFiles.Item(1).Physica lName)
strLOGfile = Trim(db.TransactionLog.LogFiles(1).PhysicalName)

'Clear out the database object
Set db = Nothing

'Detach database to allow copying
sql.DetachDB (strDatabase)

'Copy database files to new names
FileCopy strMDFfileName, strMDFfilePath & strNewName & ".mdf"
FileCopy strLOGfile, strMDFfilePath & strNewName & "_log.ldf"

problem comes when i tried to attach the db using enterprise manager, error come out :

"passed to log scan in database "SIPS' is invalid" come out ...what is the problem of this?