Concurrency does not work

[Costas]

I have the following code:

Dim RetVal As Integer
Dim objParam As SqlParameter

Dim objCmdUPDateAccInfo As New SqlCommand("sp_UpdatetbLibCompanies")
objCmdUPDateAccInfo.CommandType = CommandType.StoredProcedure
objParam = objCmdUPDateAccInfo.Parameters.Add("@CompanyID", SqlDbType.Int)
objParam.Direction = ParameterDirection.Input
objParam.SourceColumn = "CompanyID"
' objParam.Value = txtCode.Text
objParam.SourceVersion = DataRowVersion.Current

objParam = objCmdUPDateAccInfo.Parameters.Add("@CurrencyID", SqlDbType.Int)
objParam.Direction = ParameterDirection.Input
objParam.SourceColumn = "@CurrencyID"
objParam.Value = 1
objParam = objCmdUPDateAccInfo.Parameters.Add("@TaxCode", SqlDbType.VarChar)
objParam.Direction = ParameterDirection.Input
objParam.SourceColumn = "TaxCode"
objParam.SourceVersion = DataRowVersion.Current
objParam = objCmdUPDateAccInfo.Parameters.Add("@AccountCode", SqlDbType.VarChar)
objParam.Direction = ParameterDirection.Input
objParam.SourceColumn = "AccountCode"
objParam.SourceVersion = DataRowVersion.Current

' Dim strConnectionSting As String
strConnectionSting = "workstation id=IT;packet size=4096;integrated security=SSPI;data source=SQLSERVER;persist security info=False;initial catalog=DATA"
Dim objConn As New SqlConnection
objConn.ConnectionString = strConnectionSting
objConn.Open()
Dim DA As New SqlDataAdapter '("sp_UpdatetbLibCompanies", objConn)

DA.UpdateCommand = objCmdUPDateAccInfo
objCmdUPDateAccInfo.Connection = objConn

Here the dataset dsAccInfo has specific values.Next I open the database and i change the values to some fields.


DA.Update(dsAccInfo.GetChanges, "tbLibCompanies")

THe update is completed .

Where is Concurrency??