funny blonde joke!!

a blonde walks in an electronic store and asks a worker how much is this T.V?and the worker says im sorry we dont serve blondes so she goes and dyes her hair red and  goes back and asks the same thing and the worker says the same thing as before and then she goes and dyes her hair black then comes back her and the worker say the same thing as before so the blonde says ok i died my hair two times how on earth do you know im really blonde??? and the worker says because thats not a T.V thats a microwave!!!!!!!