Iphone 4s Composite AV cable

Hi There,

I have recently purchased an Iphone composite AV cable in order to watch films and stuff on the telly via my Iphone 4s. I have connected the cables into the TV and recieving sound from the telly however there is no video coming from the TV.
I have seen on other discussions that you are meant to go to settings> general > TV out which only appears if it is all connected properly but this isn't appearing even though I have checked and re-checked that they are connected properly and the sound is coming out?

Any suggestions on what is going wrong will be hugely appreciated.

Thanks,

Alex

P.s I am using ios7