case statement

is it possible to use the case exp inside a select query

eg:

select 'callduration'=
case when
starttime <>'1/1/1900' then starttime-endtime
else 0
end case from table1

Code:

---

select 'callduration=' ||
      case
        when starttime <> TO_DATE('01/01/1900','mm/dd/yyyy') then endtime-starttime
        else 0
      end case
from table1;

---