Sir, - While this may be the "season to be jolly", many parents are experiencing great difficulty from continuing demands and pressures. The stress builds up as they endeavour to produce the perfect Christmas for all, exploding sometimes with dire consequences.There are single parents, lonely and isolated, trying their utmost to make Christmas for their children. For them, the season of goodwill means continuing exclusion from their family home and non-acceptance of their parenting status.Parentline, an anonymous telephone helpline for parents under stress, is aware of the stresses: since Christmas began in November, our calls have trebled. We would like to inform your readers that our helpline (01-8733500) will remain open on Christmas Eve from 10 a.m. to 6 p.m. - Yours, etc.,Valerie Smith,Administrator,Parentline,North Brunswick Street,Dublin 7.