How do I get rid of a pattern/pin unlock???

[JillB]

Hi. I was experimenting with my Nexus 10 (5.1.1, not rooted) and set up a pattern unlock, having only been swiping until then. However, I don't really want a secure unlock on this device, so I decided to go back to simply swiping. Only I can't! The option to use swiping is greyed out, so the only change I could possibly make would be to use a pin instead of the pattern, a "solution" I don't want to use either. Can anyone tell me how to go back to swiping please? Thanks in advance for any ideas you may have.