my phone was in the middle of updating its software and then suddenly switched off and ive tried to reset it but the itunes symbol appears, I've tried to connect it to itunes but it says it needs to be restored as it is on repair mode.

My Iphone4S was in the middle of updating its latest software then suddenly it switched off, it hasnt turned on since and I've tried to reset it but only the apple sign appears then the plug into ittnes symbol. I've tried to plug it into itunes but it says my phone is on repair mode which is why it needs to be restored first in order to connect to itunes. I have also then tried to restore it but the error sign appears.