Calculate new field without blanks or NULLs

[#1]

Hey community,

I want to create a new field with the expression if([Field1]+[Field 2]<'2014','YES','NO') as [New Field]

However, I want the expression to also ignore where there are nulls or 0s in either Field 1 or Field 2. How do I do this?

[#2]

just say alt(Field 1,0)+alt([Field 2],0)