I can't hit the play button

When I log in on the launcher, the play button in the centre... I have wifi and up-to-date java so those should not be a problem. I can't even play offline... I've tried re-downloading the launcher, restarting my computer, but nothing works! Now I have to play on the old minecraft (1.5.2) and it is really annoying when I want to play with friends. Please help!