Small Engines (Lawn Mowers, etc.): gasoline in oil tank, briggs and stratton, hp briggs

Question
my son was going to mow the lawn for me while i was at work. he has done this before but i guess he forgot where to put the gas since last mowing season. he stated that he relised his mistake after only putting a small bit in and called me right away. i told him not to start the mower and wait till i got home to fix the problem. is draining the oil resevoir and replacing with fresh oil sufficient or should i do something else in addition. the lawn mower is a push type 4.5 hp briggs and stratton. thank you  

Answer
First of all how old is your son?  Can he read "OIL" on the lid of the url reservoir?  I'm just messing with you, you big silly.  Enough playing around.  Yes you should drain the oil reservoir and replace it before trying to mow.  You know how kids are.  They say a little, but the little guy could have really saturated the oil with gas.  Gas will break down the oil and it won't help lubricate the engine parts like it is supposed to.  Also tell your son not to drink the oil even though it comes out of a "resevoir!"  hahahahah Cletus you really crack me up boy.

Cletus P. Edmond

P - Stands for pretty