IIF IN ORACLE

In sql-server (or access) there is a db-function : IIF. i.e.
IIF(A=B, <RESULT WHEN TRUE>, <RESULT WHEN FALSE>);

(It should be in a select statemant !!!)

What is the equivalent in Oracle 9i.
(not decode, because decode is one value, like case statement,
I want to ask something like :
if a between 1..20 then
  <when true>
else
  <when false>
end if; Received on Mon May 08 2006 - 11:16:35 CDT