Dear All,
I am very new to VB.NET, I am using VB.NET 2005 and currently I am trying to do stock group looping process ..(see below)

I need advise from the expert .. do I already have correct codes for such stock group looping process below?

Try
    cn.Open()
    Dim cmd As New OleDbCommand("SELECT * FROM STOCKS ORDER BY STOCKGROUP,STOCKCODE", cn)
    Dim dr As OleDbDataReader = cmd.ExecuteReader()
    Dim mStockGroup as  string, mStockCode as string, mStockName as string
    If dr.HasRows Then
        Do While dr.Read
            mStockGroup = dr("StockGroup")                  
            Do While dr.Read and dr("StockGroup") = mStockGroup          ' I am not sure for this part !
                    mStockCode = dr("StockCode")
                    mStockName = dr("StockName")
                    messagebox.show(mStockCode & "   " & mStockName)
            Loop
       Loop
End if
dr.Close()
Catch ex As OleDb.OleDbException
MessageBox.show(ex.Message)
Catch ex As Exception
MessageBox.show(ex.Message)
Finally
cn.Close()
End Try