Whats wrong with my iPod touch?!?!?!

Apple! I need help> Okay so, I have an iPod touch the original model and iv'e been using it for quite some time now and never had a single problem. But, just yesterday i was using my iPod and when i went to close the app with the button on the main screen it wouldn't work the button has stopped working and i don't know what to do please help :"""""(