I agree with the previous postings - this is one dental emergency that really does have urgency. You need to see a dentist ASAP - it will make all the difference to the tooth's prognosis.
If the tooth is even partially reimplanted, keep it there until you can been seen. Bite down on as clean handkerchief, for example. This will prevent further damage to the periodontal ligament
Do not handle the root of the tooth or try to clean it.
A dentist may be able to reposition the tooth for you under local anaeasthesia. Even if not possible, it is usually preferable to retain the tooth as cosmetic treatment can be carried out at a later stage.
A dentist needs to splint the tooth in place for a period of 2-3 weeks, and ideally root canal treatment needs to be started within 24 hours.
If you own dentist does not answer, try Yellow Pages etc, but please be seen urgently.
Hope all turns out well