Did this happen all of a sudden or have you had no-starts before? Usually an engine will give an indication of trouble before it decides to not run at all. Ignition parts are always suspect with a no-run condition but it could be just about anything. Without the computer error codes, if there is any, it's a guessing game. Water in the fuel, a broken wire, corroded connector, etc, take your pick.
Any other information you can give like, whether it just happened, last time it was serviced if anything has been replaced, etc, would help alot.
Mech_Tech