facebook application feed dialogue php

i am trying to generate a feed dialogue through php to post contents 开发者_如何学Goo user's wall. i have taken extended permissions. the variables used have been defined and tested. still the code is not working. could anyone please tell me whats wrong with the following code:

{}

Obviously you have issues with your string concatenation:

$feed_url = "http://www.facebook.com/dialog/feed?app_id=" 
            . $app_id . "&redirect_uri=" . urlencode($canvas_page)
            . "&message=" . $message
            . "&link=" . $linky
            . "&picture=" . $imageurl
            . "&name=" . $name;

if (empty($_REQUEST["post_id"])) {
    echo("<script> top.location.href='" . $feed_url . "'</script>");
} else {
    echo ("Feed Post Id: " . $_REQUEST["post_id"]);
}

Also is it $linky or $link ?