Solve the case:
A man was found murdered on 26.01.1992 afternoon. His wife called the police. Police questioned everyone.
Wife: Sir, i was sleeping.
Cook: I was cooking.
Gardener: I was picking vegetables.
House-maid: I went to the Post Office.
Children: We went to play.
Neighbour: We went to marraige.
Police arrested the murderer immediately.
Who is it????