The first step to open a facebook  dialog popup using ActionScript 3.0 is to create a bridge between our swf and fbjs’ (facebook javascript) page.
In order to open a popup, facebook introdouced a fbml tag that must be inserted in the application callback page. As described in the Wiki, it’s important to put the fbjs tag:
[cc lang=”javascript” escaped=”true”]
<fb:fbjs-bridge/>
[/cc]
before the swf’s inclusion tag
[cc lang=”javascript” escaped=”true”]
<fb:swf swfsrc=”URL_SWF” width=”SWF_WIDTH” height=”SWF_HEIGHT”/>
[/cc]
and it must be followed by the script tag
[cc lang=”javascript” escaped=”true”]
<script>
<!–
–>
</script>
[/cc]

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