IF-THEN-Else Help

Hey all, need some help here.

I'm creating a life expectancy calculator - and I need some help with the if-then-else, structurally.

Basically, I need a if/then for M or F then a break down of ifs thens-

I just dont know how to structure it properly - should I do it

Basically I have a lifeExpectancy and a bunch of other variable names as I have to do this state to state.

Example:

M from WI
If M smoke then take 7 years off life expectancy

if M from WI are over 72 inches or under 66 they live two years less

and so on. Basically, I need help with nesting the If Thens Ands Ors.

Even if it is just general structure, I might be able to piece it together enough to customize my project.