cancel a running query?

[Mikael Sundberg]

Hi
is there anyway to cancel a running query? 
i know you can se the current running querys with for example: 
select XID,STATUS,SQL_TEXT from SYSCS_DIAG.TRANSACTION_TABLE 
               where SQL_TEXT is not NULL;

but if you accidently enter a query that takes forever how do i cancel it?
im using the latest derby.

/Micke