Problem with completely nested query

Hi,

I have this completely nested query:

SELECT S.sname from S where
   S# in (select S# from SPJ where 
  P# in (select P# from P where P.pname = 'Bolt') 
  and
           J# in (select J# from J where J.city= 'London')
  );

   but when I want to execute it, the execution starts and doesn't stop, in fact it doesn't execute. It says:"executing query" and nothing happens.

Can anybody help me what is the problem please?

Thanks