how to select row from datagridview when column have cells is empty

private void selectrow()
       {
           int i;
           for( i=0 ;i<datagridview1 .rows="" .count="" mode="hold" />            {
               string row = dataGridView1.Rows[i].Cells["Name"].Value.ToString();
               if (row =="")
               {
                   sqlconn.Open();
                   string sqlquery = "select * from tbl... where id='" + dataGridView1.Rows[i].Cells["id"].Value.ToString() + "'";
                   SqlCommand sqlcmd = new SqlCommand(sqlquery, sqlconn);
                   SqlDataAdapter sqlda = new SqlDataAdapter(sqlcmd);
                   DataTable dt = new DataTable();
                   sqlda.Fill(dt);
                   dataGridView1.DataSource = dt;
                   sqlconn.Close();
               }
           }
       }