Help with formulae
 

I have in WB A four cols, (Date,Details,Credits,Debits) which are
constant and rows which are added to every day.
In WB B colA I would like a formula which enters the date and in colC
either Debit or Credit, provided that certain criteria are met. e.g if
the entry under Details (WB A) says Mr Johns then the date of that
entry and the Credit amount would appear in WB B, colA being for the
date and colC for the amount
I hope this makes sense and that someone can help.
Regards
Joe