Kentico V7 Form - Disable paragraph format

Hi

I'm trying to modify the content of a long-text variable in a form on CMS; but the HTML editor sets the content of the variable in one of the options of the paragraph format dropdonwlist (in this case selects "Normal") ; so if i try to insert a simple text and a branch tag, the editor puts the paragragraph tags "p" and inserts the content of the variable.

Is it exits a way to disable this action?

Thanks