Small Engines (Lawn Mowers, etc.): no spark, engine model type, key switch

Question
I have a murray Model# 42591x8b with a 17hp engine. I recently tried starting my riding mower and started but died. I then wore teh battery down and had to put it on a charger after charging it i again tried to start it but would not start, however after i turned of the key the start kept turning the motor over so i hit by the selnoid and it shut off. I then tried to start it again and the motor cranked over with no problem however would not start. I checked the spark and found i had no spark to either spark plug. what can i do to resolve this issue and what parts do i need to buy?

Answer
Can you send me the engine model, type and code number?  Have you checked the safety switched.  Follow the wires from the key switch to each safety switch; seat, deck and clutch.  Dis-connect and re-connect each connection to ensure nothing it corroded.

Let me know the engine info and the outcome of checking the safety switches.
Eric