I'm using an iphone 4s for one year?

Now i'm planning for iphone 5c. I'm confused if i should really go for 5c or continue with my 4s. I havn't had any problem with my 4s till last week. Now i'm facing a problem which just gets hanged in the lock screen and i'll have to restart the phone to bring it back to work. I'm in a serious dilemma. Ppl please help me out.

Time, to upgrade

Get the Galaxy Note 3! Way better.

If you are iPhone loves and using 4S then you should have to planning for iPhone 5S. Anyway your 4S need upgradation after it will work fast and properly.