Not a TV its a microwave

One day a blonde walked into a store and said
“I`d like to buy that TV.”
The salesman said “Sorry, we don’t sell to blondes.”
The blonde went home and dyed her hair red. She went back to
the store and said “I�d like to buy that TV.”
“Sorry we don’t sell to blondes.” The man replied again.
She went and dyed her hair black, then returned to the store
and said “I�d like to buy that TV.”
Again the man said “Sorry we don’t sell to blondes.”
The blonde finally asks “How did you know I was a blonde?”
The man said “Because that�s not a TV its a microwave.”