Minecraft not loading pass Mojang screen on pc?

First of all i'm running vista and i did the horse update for mine craft but then i stopped playing for a while. When i came back i tried to load mine craft but. When i hit play on the 1.3.7 launcher it goes to the Mojang screen then quits, heads back to the launcher screen and if i do the same thing again, it also does the same thing, now i have tried: restarting computer and re-installing java.