Lights dim when electrics used.

[smileynialley]

thanks for the replies,
I have had a look around the engine bay and there is nothing obviously loose or corroded etc.
It seems like the alternator can't produce enough power to power everything in the car so when you use the windows or brake lights etc, the headlights and cabin lights either dim or cut out altogether and the stero cuts out.
No affect on the engine though.