Many people have complex shailos that come up when there is a 3 day Yom Tov because they forget to make an Eiruv Tavshilin.
Worry no longer.
A free service was recently started where email reminders are sent on Erev Yom Tov to remind people to make an Eiruv Tavshilin. Spread the word. Sign up: http://www.eiruvtavshilin.com/