Cause for T-Log become Full and how to reduse it

Hi,
i would suggest to refer below KBs and threads ,for cause of Transaction Log becoming full and how to reduce Locks and how to stop it :

Causes of SQL Transaction Log Filling Up

http://support.microsoft.com/?id=110139

http://www.support.microsoft.com/?id=317375

How to stop the transaction log of a SQL Server database from growing unexpectedly
http://support.microsoft.com/?kbid=873235

and threads:
http://groups.google.com/group/microsoft.public.sqlserver.server/browse_thread/thread/391579b8149281a4/b40ed8742075475d#b40ed8742075475d?sa=X&oi=groupsr&start=1&num=3

http://groups.google.com/group/comp.databases.sybase/browse_thread/thread/4ad5e6818968385c/fac9ed81dd813cd9#fac9ed81dd813cd9?sa=X&oi=groupsr&start=0&num=3

http://www.dbazine.com/sql/sql-articles/mullins-sqlserver


HTH
Regards