Went out for shopping, parked my car, came back, the car wont start. The starter is working fine, but the engine wont start.

Inspected the wires and spark plugs, all seem fine. A friend of mine who knows cars came over, we took the distributor apart and he held a metal screwdriver next to the rotor and i tried to start the car and he said there was no spart. He is saying it is likely that the distributor is dead. How can i find out for sure that it is the distributor - b/c if it is, i will buy one online for a lower price, rather than getting ripped off by the dealerships