It's the way SQL Server (and other RDBMS) are designed. Every operation is written to logged before it's actually done. This way you can manage transactions that will be atomic.
Someone else can go deeper or you can read the Stairway to Transaction Log Management in SQL Server[/url]
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2