You need to manage that log better
Please read through this - Managing Transaction Logs[/url]
Do not ever delete a database's transaction log. SQL cannot always recreate the log, only if the database was cleanly shut down prior. Deleting the log can result in the database not attaching and a restore from backup being needed.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability