....the man and his wife who are awoken at 3 o'clock in the morning by a knock on the door? The man gets up and goes to the door where a stranger is asking for a push.

''Not a chance'' says the husband -- ''It's three o'clock in the morning!''
He closes the door and returns to bed.
''Who was it?'' asks his wife.
''Just a stranger asking for a push'' he answers.
''Did you help him?'' she asks.
''No I didn't -- it's three in the morning.''
''Well you've got a short memory'' says his wife.
''Can't you remember about three months ago when we
broke down on holiday and those two guys helped us?
I think you should help him.''
The man does as he is told and returns to the front door and calls out into the dark ''Hello -- are you still there?''
''Yes'', comes the answer.
''Do you still want a push?'' calls out the husband.
''Yes please!'' comes the reply from the dark.
''Where are you?'' asks the husband.

''Over here on the swing'' the man replies.