im getting the dreaded:  
Object reference not set to an instance of an object.
on the code below. pretty new to C# but i know im missing something basic here.   

any help is appreciated
thanks
rik

public void GetEEs()
        {
           
SqlConnection myConnection = new SqlConnection("Data Source=(Local);Initial Catalog=A39;Integrated Security=SSPI");
SqlDataAdapter da = new SqlDataAdapter("GetAuditTimeCard",myConnection);
            da.SelectCommand.CommandType = CommandType.StoredProcedure;
            da.SelectCommand.Parameters.Add("@PERIOD",SqlDbType.DateTime,8);
            da.SelectCommand.Parameters["@PERIOD"].Value = txtPpe.Text;
            DataSet ds = new DataSet();
            myConnection.Open();
            da.Fill(ds);
            Dg1.DataSource = ds.Tables["TimeCard"].DefaultView;
            Dg1.DataBind();
            da.Dispose();
            myConnection.Close();
}