What is wrong with you

Murphy wouldn't work. The last job he'd had was school milk monitor. He tried every trick in the book. When he left school he joined every union so he'd always be on strike. Lately he'd taken to being permanently ill. His doctor was at least a little involved in the plot, until one day:

'Look here, Murphy,' said the medico, 'I've given you every complaint known to medical science. You've had trench foot, mustard-gas poisoning, morning sickness. I can't think of anything else.'

'Just put anything down,' said Murphy. 'The DSS don't look that closely.'

So in the space where it said 'Illness' the doctor just drew a line.

Back at the DSS office the clerk looked at the sick note and said:

'It doesn't say here what's wrong with you.'

'It does so,' said Murphy, pointing at the line. 'I've had a stroke!'