I need to help for write condition

dear all,
i want to write a condition for if first condition do not be, not make sell,
if condition 1 is ok then goto condition 2 and write result.

condition1=Ref(diff,-1)<4 AND diff>4;

if it is right then look (condition2),

condition2=Ref(d,-1)<70 AND D>70;

and write result,

for examle sell=......

Thank you for your help...