As de title says, in Designmode on a Iframe (for a WYSIWYG editor) I get an <br /> in FF and a <p> in IE when using ENTER.

Now I found severall solutions to change IE's <p> to a <br />
However I want to change FF's <br /> to <p>

In de Mozilla Docs I found "insertbronreturn" which can be used for changing the behaviour, however this aint working

Code:
document.execCommand('insertbronreturn', false, true);
Anyone a clue ?