Averaging 2 fields

[sopomeres]

I'm using CR 8.5. I have a numbers value in 2 different fields. How can I average these 2 seperate fields using a formula field? Also, if field1 = 0 then the field 2's value will be displayed as the average. So, 0's need to be omitted somehow.

Example #1:
Field1 = 90, Field2 = 100 Average = 95

Example #2:
Field1 = 90, Field2 = 0 Average = 90

Thank you for your help.

 

[JeroenBoon]

something like
create formula field "Average":
if
Field1<>0 and Field2<>0
then
(Field1+Field2)/2
else
Field1+Field2

 

[sopomeres]

Thank you JeroenBoon it worked!