How do you get a frowning face on your avatar?

Question

I don't know how to do it but Ive seen it before

and Ive seen other hidden things how do you get to these?

Answer 1

It is simple

go to profile

edit my info

click on pictures and go to your avatar

it will say edit my avatar

above your avatar but below the word preview

are some expressions.

your choices are smile, special

sad or angry

The sad would be close to frowning.  

when you are done close out screen

press preview at the bottom

then okay

Answer 2

go to the yahoo avatars website and change its facial expressions.There's links at the top of your avatar with the option to change his expressions.