Dim sd As DataTable
k=this.Tables[Persona]


        Dim ap = New ApplicationClass()
        Dim wbk As Workbook
        Dim oMissing As Object = System.Reflection.Missing.Value
        wbk = ap.Workbooks.Add(oMissing)
        Dim sht As Worksheet
        sht = wbk.Sheets(1)
        Dim cmd As OleDbCommand = New OleDbCommand("SELECT Username,Pass FROM Persona WHERE [Username]='" + TextBox1.Text + "' AND [Pass] ='" + TextBox2.Text + "'", m_conn)
        Dim myReader As OleDbDataReader = cmd.ExecuteReader()

        for i=0 to i<k.Rows.Count step i++

            for j=0 to j<k.Columns.Count step j++