Adjusting Volume on my Ipod Nano

Question

When I try to adjust the volume on my Ipod Nano under Settings it is asking me for a code.  How do I reset the code or find out what the code is?  Is there another way to increase the volume, it appears to be locked and is very low.  I need to unlock the volume so that I can increase it.  The screen I see is almost like a combination lock.  Can you please help me?

Thanks,
Jennifer