A bloke at work got his contract cancelled the other day for having to much time off ill but then he did use to say "I'm going out tonight for a few beers with my mates" then not turn up the next day, wasn't hard to work out he wasn't ill.
Personally I tend to go in when I have a cold unless it gets too bad, shows dedication if you go in sick

got sent home the other day when I was ill, the boss told me to go home, I said I'd be alright but then she insisted, I wasn't going to refuse twice
Felt a bit guilty going on the lash the same night as well but then I had made arrangements to go out already so it was tough.