Small Engines (Lawn Mowers, etc.): Wrong oil, plug drain, weight oil

Question
Hey Eric,
I recently filled my pushmower with the oil that I am suppose to mix with gas (I forget the name of this type of oil). At any rate, my Dad gave me this type of "mixing" oil for my blower, weedeater and trimmers. Once I realized I had filled it with the wrong oil, I tried to start the mower, but it never started ( it could have been that I needed some gas too). So, what can I do to save the engine to my lawnmower?

Please help!
Tonya  

Answer
Remove the spark plug.  Drain the wrong oil and refill with SAE-30 weight oil.  

Replace spark plug with a brand new one and refill with fresh gasoline, less than 30 days old.
What brand of mower do you have and what brand of engine is on the mower?
Let me know.
Eric