Need three things.
1. What is meant by 'no spark'.
2. When did this happen, and explain what happened. In other words, condition when 'no spark' occured.
3. Type of ignition system.
Without these it would take hours to type out the possibilities.
Car could have been driving down the freeway and the engine died, or the key was turned to start and nothing happened.
Very different situations to diagnose.
It may not even be a spark problem.
Nothing to go on here.