reply to SuperNet9
Re: URGENT Furnace stoped working! Can you see if the Gas valve is a Honeywell one? If so, it is probably a "Smart Valve" one. Well...those are not so smart because a whole lot of them were faulty and would go bad prematurely after a number of years. My Gas Pack furnace had one and it went bad. You could bump it and it would start working but maybe not again on the next cycle. Of course the unit was well outside of any warranty so I had to pony up several hundred bucks for a new valve. Was only charged .5 hour of service call because I diagnosed the problem for them and all the HVAC guy had to do was change it. My unit is from 95 and is still going. It does have electronic ignition instead of pilot light. Google "Smart Valve" and you will see what I am talking about.
Also make sure the fan for the gas exhaust is working. The moisture from the burning gas can cause these to rust or fail. This happened to my neighbor after only 6 years. Fan rusted and broke apart causing unit to overheat in the heat exchanger because the gas was not getting pulled though.