I have a problem with my hall and landing lighting. Downstairs is a two switch light fitting, upstairs landing is a one switch fitting. The downstairs light has two sets of wires supplying power to the switches, each wire carries one red and one black wire. the light fitting has two gangs labelled "L" at the top and "L1" bottom left "L2" bottom right. I have tried to wire the switches as per the lighting diagram which came with the switches but I'm having problems. I can get the downstairs only working via gang one, red wire in "L" and black wire in "L1", but no matter how I wire the other gang and the upstairs switch I cannot get the upstairs working. I need to wire upstairs so that it can be switched on and off using both switches upstairs and downstairs. The below drawing shows the set up, can somebody please let me know how to wire these switches so both lights work. nb the old wiring system had a small 2inch red 'flywire' but I'm not sure what this was for.