procedure Tfnewquery.CheckBox1Click(Sender: TObject);
begin
select_field(DBGrid1,checkbox1,0);
end;
procedure select_field(dbgrid:Tdbgrid;checkbox:Tcheckbox;index:integer);
begin
if (checkbox.Checked=true) then
dbgrid.Columns.Items[index].Visible:=true;
if (checkbox.Checked=false) then
dbgrid.Columns.Items[index].Visible:=false;
end;