How to give if else conditions Crystal report

Question

I  hv used this code

if {condition 1}=0 then crYellow

else if {condition 2}=true then crred

else if {condition 3}=true ||  {condition 4}=true   then crred

else crwhite;

bt still hving problm i.e. it satisfies I,II conditon bt didn't satisfy III and IV 

pls help me out