Your going through puberty, its perfectly normal! The way to stop it is wait until you grow up a little more!

its gonna raise it's little head at the very moment you let your guard down!!!!!Be AFRAID be very afraid!!!! it's no big deal the older you get the better and more confortable you will be about it... it all stents from underlying thoughts from being a meal....your unsure for one....second....you titty-spane is almost at it's peek of 13seconds(rate thinking about boobs) your best bet is to just not draw attention to it...and the more nervous you are about it the more often it will happen....so thr first step....don't worry....stress can have the opposit effect of a male without ED which is a few extra times than would be liked....you will grow out of it...it took me afew years...

Dude it's normal for someone your age! Don't worry about it. It means you're a healthy boy!

The only cure is constant masturbation. :)

Jack off. It's the only way.

you need to milk your snake more often

it probably has a lot to do with the way that female students dress. it's only natural to be aroused by visual stimuli. since you can't control how some trollops dress, just look away and think of some serious situation and maybe it will pass.

take mjs advice (JUST BEAT IT)

Try taking your hands out of your trouser pockets.

dont wear boxer shorts. wear skivies that are tight fitting. its about what you are thinking about. rather than what the trollops are wearing. you could start memorizing poetry and when the situations arises, just say the poem you have memorized.

Start wanking it daily and if you get a woody in school, find a secluded spot and place it north between your waist and your belt so it sits tight until it cools off and nobody notices.

Jackin' it off fairly often, say once or twice a day is the only way...that and if it keeps up (no pun intended)then wear something that'll make it so you can tuck it in and hide it.

Don't worry about it man. It is a normal part of life. Just be thankful that it is happening. The older you get, the less your penis will get hard. So enjoy it while you can.

It happens because you're a teenager, and your hormones are going crazy right now. There's really not much you can do about it, but it WILL eventually settle down.

You require sex.

masturbate more often.

"At this age it is completely normal for this to happen to you. This can happen up to 20 times a day for no reason at all. You are in the midst of puberty and this is exactly what you and all the friends you have are seeing also. You do not need to think any sexual thoughts at all. This happens in a classroom or just walking and at home and it goes away. The slang term for this is a "boner". Your friends have the same problem. The only real problem is that it is embarassing to you especially at school if you have to get up and change clsses. Most guys will pull their shirt out to hide it or carry their books in fron of them to hide it. This is going to continue for a number of years. As your body produces more testosterone you will see other changes in your body as well. But having erections is part of being a teenage boy. You do not need to do anything about it. Boys your age and younger eventually get into masturbation but this is not always convient when this happens. Masturbation is not a sin as many believe. It is Gods way of allowing the unmarried to relieve the sexual tension that they feel at times in their live. You will never get any disease or do harm to yourself or make a girl pregnant through masturbation. Its completely harmless and there is not a guy in the world no matter what his culture is who does not engage in it. If someone tells you they do not then you can be sure they are lying." Source and further information: http://en.allexperts.com/q/Teenage-Problems-1458/2008/10/UNCONTROLLED-ERECTION.htm

Don't think about nuns...it doesn't work. You just start to notice that some nuns are kinda hot. And it will stop, trust me. At 48, it's a problem I could live with.

hang around uglier girls? haha joking!

it's normal man your going through puberty right know all it means that it works and it'll go away eventually

Stop taking Viagra