i Need help change the user Role

Hello i neeed help i have intall the facebook conect button to my wordprees
http://frasespropias.com/ is a blog for publish you own phrases ok soo i want the user use the facebook conect button
http://frasespropias.com/wp-admin/post-new.php cant post with out register withc only the conect button the problem is when you conect in the facebook conect you a subcribe and the subcribe cant post i want to do the subcribe cant post in my blog i download a lot of plugin to change the role of the user but nothing work plaese i neeed helppp plaese

the plugin of facebook i use is Facebook Connect the other option for me is change the defect role conect user in the facebook plugin of subcriber to author or editor

plaese helpp