I have a commission statement that I need to set functions in.

I need to say if cell C30 is less than or equal to 20, then C31=$40, if C30
is between 21-40, then C31 is $60, if C30 is between 41-50, then C31 is $80,
and if C30 is greater than or equal to 51 then C31 is $100.

Please Help!!!