Whats wrong with the sql syntax below?
  /*distinct number of person numbers with D11*/
 select distinct person_number from
 /*select which ones of the 1000 have D11*/
 (select event, person_number
  from table
 where event = 'D11' and person_number in 
 (
 /*top 1000 */
 select distinct top (1000) person_number
  from table with (nolock)
 where client = 3
 ))
 
     
    