A blonde in Las Vegas

In Vegas, a blonde walks up to a Coke machine and puts in a coin. Out pops a coke. The blonde looks amazed and runs away to get some more coins.

She returns and starts feeding the machine madly, and of course the machine keeps popping out the drinks.

Another person walks up behind the blonde and watches her antics for a few minutes before stopping her and asking if someone else could have a go.

The blonde spins around and shouts in her face: "Can't you see I'm winning?"