How do i fix my Mac webcam problem?

I've recently bought a new macbook and the webcam worked perfectly. Now that i opened photo booth, i cannot see my picture and a black screen is displayed even when i take the picture. Also, theres a green light next to the webcam which is on even when photo booth is not active. Can anyone who had this kind of problem show me how i can fix it?

I already restarted the computer and trying to reinstall the program but have no idea how to, i just switched from a pc so everything is pretty new to me.;P

Make sure that it is showing in System Profiler, under the USB section.

You might want to try resetting the SMC & Resetting PRAM

It means that another program is using the webcam. This is why you're not seeing anything when you try to use it, because your webcam can only be used by one program at a time. Check what programs you're running and if you can't find a fix, take it into the store.

Not to freak you out, but some people use software to spy on people through their webcams - others have found this to be the case when their webcam is on all the time.