Check the consumer unit (fuse board) for a tripped breaker of a blown fuse.
If that's all OK then call an electrician - your question strongly suggests a certain lack of familiarity with things electrical which could be dangerous...
Lord Finchley tried to mend the electric light
Himself. It struck him dead: And serve him right!
It is the business of the wealthy man
To give employment to the artisian.
Good luck... Take care...
Peccavi
June 2009