<br> instead off <p>

Hi
Iam new to the FCK-editor. I got everything to work but I have <p> as default off CR. I want to have <br> and not <p> when I hit return. I try this code inside FCKConfig.js

FCKConfig.EnterMode = 'br' ;
FCKConfig.ShiftEnterMode = 'p' ;

I still got <p>. How do I solve this?
Please help.
Best regards Stefan