Challenge to live for 24 hours

One day a boy asked his girlfriend 2 marry her.
The girl gave him a challenge to live a day with out her,
only then she will marry him.
no communication was there for 24 hours.
the boy didnt knew that the gal has only 24 hours life left.
becoz she was ill. after 24 hrs the boy went to the gals house holding a ring.
he was shocked to know that she was dead.
she left a letter for him saying,
"U DID IT AND U CAN BE WITH OUT ME.
DO IT EVERYDAY MY LOVE... MISS YOU....!"