can’t edit the templates

Hi,
I am very new to WordPress, just started yesterday, but I have heard with friends who knows it and nobody can help me.

I delete some code from the templates, and hit “update file”, the page loads, but nothing has happened to the code. Anyone knows what the problem is? As I said, I am really new to this, so it could be that I have hit a “read-only” button or something.

All help is much appreciated

-Einar