Binding gridview according to login person data?

protected void Page_Load(object sender, EventArgs e)
{
   SqlCommand SelectCommand = new SqlCommand("select Id,Title,owner from PostAd1 where owner=@owner",conn);
   SelectCommand.Parameters.Add("@owner", SqlDbType.NVarChar);
   SelectCommand.Parameters[0].Value = Convert.ToString(Session["username"].ToString());
   SqlDataAdapter da = new SqlDataAdapter(SelectCommand);
 
   da.Fill(ds);
   Gridview1.DataSource = ds;
   Gridview1.DataBind();
}