I tried to update my phone from IOS 7 to IOS 9. it goes through a first slide to upgrade once that is done i get a screen that says slide to set up. then it says update complete your Iphone was updated successfully. there are just a few more steps to follow, and then you're done. then i hit continue and it takes me to a screen that says slide to upgrade, but it does not let me slide. i'm not sure what to do. I already tried to restart the phone by holding in the home and off button at the same time and it did not do anything. I'm not really sure what to do.