I need to create a formula wich contains an if clause and a validaiton (list).

A1= will be "member" or "non member" (will be selcted from a list: ok)
A2= 0.30 is A1="non member" and 1.0 A1="member" (if clause: ok)
A3= amount will be entered (manually)
A4= if A2="non member" then will ask for "Yes" or "No" (as validation) and
if A2="member" will return as "Recorded"

Thanks for your help.