i am confused as to how to wire up my two way switch... i have run a 1.0mm twin and earth cable from one switch to the other & i am stuck as to how to wire the switches...on the back of each switch there is the usual common ,at the top & L1 & L2 at the bottom, and the wires are red(live(,black(neutral) & earth, i know it is simple because i have done it before...but i just cannot remember how!!!!!!!!!!!!!!!please help