while not dm1.TBLEnvases.eof do
Begin
dm1.Qtemp.SQL.clear;
dm1.Qtemp.SQL.Text := 'Select DISTINCT ingre.codenvases, (sum(Ingre.Cantidad)-Sum(Egresos.Cantidad)) as Stock, '+
' From Ingre, Egresos where ingre.codenvases = Egresos.codenvases '+
' and ingre.codenvases = ' + dm1.TBLEnvases.FieldByName('codigo').AsString ;
dm1.Qtemp.open;
vartext1 := dm1.Qtemp.FieldByName('Stock').AsString; end;
end;