convert p to br on tinyMCE

Please help. I use tinyMCE as inline editor. So I need that when user in edit mode press enter then will be <br /> not <p>. I read manual and FAQ and try

tinyMCE.init({
            'height' : '100%',
            'widht':'100%',
            'content_css' : styles + ',/sdtc-new/nc/interface/common/css/mce-editor.css',
            'mode' : "specific_textareas",
            'editor_selector' : prefix + o.id,
            'theme':'advanced',
        开发者_如何学Ctheme_advanced_buttons1: o.buttons.join(','),
        theme_advanced_buttons2 : "",
        **theme_advanced_buttons3 : "",
    force_br_newlines : true,
        force_p_newlines : false,
        forced_root_block : '' // Needed for 3.x**
        });

But it's not work . Actually some time it's work like when I delete all conetent in edit area and type new text. But i need that it works all time. Please help. Version of tinyMCE 3.4.4

You will need to set

tinyMCE.init({
   forced_root_block : false,
   force_br_newlines : true,
   force_p_newlines : false
   ...
});

Here is a helpfull section of the tinymce FAQ.