emission warning light

[slater170]

hi there
last night while making a short journey the amber emission control warning light came on.
3o seconds after starting the car this morning the light went out, i have driven 50 miles today and the light hasnt come at all,
was making another short journey tonight and the light came back on coincidentally when i switched my windscreen blower on!

any ideas as im baffled

 

[chris a4 128]

as it happpens my warning light came on today. i have never seen it before but i will moniter it through week and if it stays on i will take it in.