Forms 3 - Order by in Block Def'n

Situation:
two blocks in Form. block A is a control block. block B is based on a table. according to criteria entered in block A certain rows are returned in block B.
Problem:
 i want to sort the rows in block B so that surnames that exactly match the search criteria in block A are sorted to the front. So i tried: order by decode(surname,:a.surname,1,2)

Oracle complains that there is a right parenthesis missing because it does not like the '.' following the block name. If i am not allowed to use field names (or block names) in the order by, how else can i do this? (i tried using a :global - didnt work either)

pre-thanks

-- 
Steve Corbett.             vvvv
Fremantle Australia.     [ o  o ]    
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