Lost ford focus central locking fob?

I lost my 2005 ford focus keys got a new one cut but it only opens the one door and starts the engine it has no fob with it is there anyway i can buy a separate fob and set it up with the car any ebay links and youtube links would be much appreciated

The best way to make sure it all works properly is to order a new key with remote from a Ford dealer, and get them to programme your car to match the chip in the new key.
Anything cheaper is a risk.