Peugeot 206 - fuel reset; how do I do it?

[Schermerhorn]

In my Passat or Golf, I just fill the thing with diesel and press the needle and it resets the fuel meter reading to 0.

I try doing the same in my sister's 206 and it just toggles between current miles done (since last reset) and total miles covered. I'm trying to work out the MPG in the little bugger but having very little success doing to.

I've read the manual but can't find much in there.

[rfn]

Push it once so it is on the trip computer.

Then press and hold the button and it'll reset.