can't send or receive picture messages

I recently updated the iOS on my iPhone 5S & since then I have not been able to send or receive picture messages, where I used to be able to click on the photo symbol in the messaging it is now greyed out. When I try to go into the pictures & select one it doesn't give me the option to send it through messaging like it used to. I have gone into my settings - messaging but it doesn't give me the option to turn messaging on & off (other then iMessaging.) I've tried turning my phone on & off, tried resetting it by holding the power & menu button. Nothing seems to be working. Any help would be appreciated! Thanks