Don't use sysprocesses, it's deprecated, included only for backward comparability and will be removed in a future version.
Use sys.dm_exec_requests and/or sys_dm_tran_locks.
The way to 'unlock' a table is to kill the connection holding the lock, or wait for that connection to finish what it's doing and let SQL release the locks.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass