case statement help

[avuong6]

anyone know why this case statement doesnt work? the conditions work individually. but when i nest them, it fails.

case when (?P_Budget1?=?P_Budget2?) and (?P_Period1?=?P_Period2?) then ' '

i also tried concatenating them too which didnt work.
(?P_Budget1?||?P_Period1?=?P_Budget2?||?P_Period2?)

[krishdw85]

keep end in the end