I basically need help with a formula I'm trying to put into a work sheet.

Think I need 3 fields, 1 is a rating which will be 0-100.

2 is a currency field

and the 3rd one is where I need it to work out a percentage of the currency in field 2.

I'm ok with that if the percentage was a constant, which it isn't.

I need it to determine what percentage to use by the number inputed in field 1.

i.e

0-50 = .05

51-60 = .1

61-70 = .15

71- 80 = .2

and finally anything over 81 = .25

any help would be much appreciated

cheers matt