Truncating SQL transaction logs

I am using Networker 7.3.1 on Windows 2003. When I backup up a SQL client, the database and the log files are backing up successfully and both can be restored fine, but the transaction log is not being truncated. I have a 1.2 GB database with a 50 GB log file. Now I am going to have storage space issues if it continues to grow.

I am performing a Full backup each night.

Using SQL 2005

Not sure how to correct this?

Message was edited by:
Mike Haupt