How to diagnose Pneumonia and how long does it need to say

it is pneumonia not regular flu under high fever? I plan to complain

my daughter's pediatrician's wrong diagnosis. After her 4 days high fever,

he just listened to her chest and back and arbitrarily told me my daughter just

got some virus and let it run its cource and don't worry because he already eliminated

flu using his meter by taking her nose swab. He made a big mistake, I need to let him know

his unprofessional behavior. Thanks.