procedure TDOC_BILL.DataGridClick(Sender: TObject);
var
i, j: Integer;
begin
if DataGrid.SelectedCount > 0 then
with DataGrid.DataSource.DataSet do
for i := 0 to DataGrid.SelectedCount - 1 do
begin
j := j + FieldByName('F_JS').AsInteger;
edit1.Text := IntToStr(j);
end;