2002 has no spark at plugs

[FOURZS]

My 2002 Altima (4cyl., 55,000 miles and out of warranty) started and ran for about 3 seconds. After that it would not start. After doing some checking, there isn't any spark at the plug. I've checked fuses hoping it would be a simple fix but have found all OK. The car has been running great. No problems starting in any type of weather.

Can some one shed some light on what may be causing no spark at the plugs. There is no distributor so the old school stuff doesn't come into play, i.e., everything is electronic. Your help and timely reply's are greatly appreciated.