Multi-Record Block - Select All Funtionality Using Forms Personalization

Hi,

I have detail level block with check box for each record.

I want to have a functionality like, with one button click - I want to check all detail records

I tried to achieve using Special Menu. But in Built in Procedure , It is not taking

= '

BEGIN

GO_BLOCK('XXX');

FIRST_RECORD;

:BLOCK.ITEM := 'Y';

EXIT WHEN :SYSTEM.LAST_RECORD = 'TRUE' ;

END

'

Please let me know any solution