Recently my IPad has stared to time otu after about 30 seconds of no activity. For example if i am reading a book and stop to blow my nose in 15 seconds or so ther screen darkens and then goes black. I then have to move the slide and reenter the passcode to go back to where I was. I would like to increase the time before the screen goes blank. I have downloaded both the original manual for the 1 and the new manual for the 2 but can not locate how to adjust the time out. Appreciate any help someone can provide on this issue.