We have a new Sony Bravia KDL-37EX503 and a new Sky HD+ box connected to the HDMI4 input on the TV. When I switch on the TV either using the Sony remote (green power button) or the Sky remote ('TV' + circular power button + 'Sky') the TV defaults to showing a digital terrestrial TV channel, at the moment ITV3. How do I get it to automatically show the HDMI4 input (the Sky box) by default when I switch it on?

I apologise if this is a very obvious question but I've read the i-manual and looked on this website and can't figure it out.  I can use the Sony remote to change the input to show the Sky box but some members of the household can't, being technophobes! Plus it's a pain to do this every time.

Any help gratefully received, many thanks!

Deb.