Facebook App extended permissions

I am making a FBML facebook application. Currently, when a user visit my application for the first time he is asked to allow his profile details to be shared or not. I want the user to be asked for publish_stream permissions i开发者_运维问答n the same login screen. How can I do this?

As far as i know the way to do is redirect the user to a url like:

<fb:if-is-app-user>
<!-- your normal code -->
<fb:else>
<fb:redirect url="http://www.facebook.com/login.php?v=1.0&api_key=[your_app_key]&next=[your_canvas_page_URL]&canvas="/>
</fb:else>
</fb:if-is-app-user>

I guess my URL is wrong because of the fact there is no place to insert the comma seperated list of permissions that I require!!!

The actual link where the user should be redirected is following:

<fb:redirect url="http://www.facebook.com/login.php?v=1.0&api_key=xxxxxxxxxxxxxxx&next=http%3A%2F%2Fapps.facebook.com%2Fxxxxxxxxxxx%2F&canvas=&req_perms=publish_stream"/>

Listen, Facebook changed their policy to ask for extended permission during authentication. Visit this link to learn more.