Armature invisible? please help!

Hi,
In the Editing Buttons of an Armature I clicked on one of those Display Options Buttons with the circles in them so I couldn’t see the bones anymore, and making new bones is impossible to me because I dont know how to connect bodies with bones. I’m very new at working with blender so I don’t know how to make the Armature visible again because I can’t select them either. So please tell me how to make those bones.