Driver side door systems don't seem to respond!?

I have a golf MK5 and the driver side door does not seem to respond. The door doesn’t automatically open with the key when you click the open button whereas the other doors do, however the door does open manually i.e. the old fashion way – put the key into the slot. Since the door doesn’t respond, it means that all the electrical/automatic systems on that door don’t work either - the petrol tank does not open, the windows don’t roll up/down and nor does the automatic lock/open system for the other doors work.
CAN ANYONE HELP!?