connectionstring in web.config
<add name="TESTDB" connectionString="Server=XXXX\XXXXX;Database=XXX;User Id=XX;Password=XXXX"/>

Public Class clsDatabase
Private Function getConnection() As SqlConnection
        Dim sConnect As String
        Dim oConn As SqlConnection
        sConnect = ConfigurationManager.ConnectionStrings("TESTDB").ToString
        oConn = New SqlConnection(sConnect)
        oConn.ConnectionString = sConnect
        Return oConn
End Function
Public Function executeSqlCommand(ByRef oCommand As SqlCommand) As SqlDataAdapter
            oCommand.CommandType = CommandType.StoredProcedure
            oCommand.Connection = getConnection()
            oCommand.Connection.Open()
            oCommand.ExecuteNonQuery()
            oCommand.Connection.Close()
            Return New SqlDataAdapter(oCommand)
End Function
End Class

Public Class clsOrder
Dim oSqlCmd As SqlCommand
Dim oDataAdapter As SqlDataAdapter

oSqlCmd = New SqlCommand("CheckAvailabilityAndUpdateOrderState")
oSqlCmd.Parameters.AddWithValue("@ord_id",  Me.Id)
oSqlCmd.Parameters.AddWithValue("@ord_ost_id", Me.OtherId)

oDataAdapter = oDb.executeSqlCommand(oSqlCmd)
oDataAdapter.Fill(oDataSet, "XYZ")
End Class