Datagridview error when trying to open a form
private void dataGridView2_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
{
  System.Data.DataRowView SelectedRowView;
  waterDataSet.DEMRow SelectedRow;

  **SelectedRowView = (System.Data.DataRowView)waterDataSetBindingSource.Current;**
  SelectedRow = (waterDataSet.DEMRow)SelectedRowView.Row;

  frmWater WaterForm = new frmWater(this);
  WaterForm.LoadWaterAcct(SelectedRow.WATER_ACCOUNT, null);
  WaterForm.Show();
}

public void LoadWaterAcct(String waterAcct, String tableName)
{
  aRTableAdapter.FillByWaterAct(waterDataSet.AR, waterAcct);
}

private void dataGridView2_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
{
  var selRow = this.yourDataGridView.SelectedRows.FirstOrDefault();
  // or
  // var selRow = this.yourDataGridView.Rows[e.RowIndex];

  if (selRow != null) {
    var selRowData = selRow.DataBoundItem as waterDataSet.DEMRow;
    if (selRowData != null) {
      frmWater WaterForm = new frmWater(this);
      WaterForm.LoadWaterAcct(selRowData.WATER_ACCOUNT, null);
      WaterForm.Show();
    }
  }
}