Ideal Boiler is no longer working properly?

I have an Ideal Classic boiler. I guess it's around 15 years old as its age is comparable with the house. I've just turned it on after a dormancy through the warmer months and a few days ago it stopped working. The pilot light will not ignite with the 'on/off' switch. It's getting colder by the day and I have no hot water or heat. Help!