No Sound!

I have an IPhone 4S. I listen to music a lot on it. The other day I tried to listen to music without head phones, ( so the music would come out of the speaker in the phone) . I tryed playing a song and no music came out! I tryed a few different songs too! I tryed turning the sound up and down on the screen, but when I tryed with the buttons it said headphones. I pluged the headphones in and I could hear the music! I'm also not getting sound in games and stuff too!

HELP!