Amfphp service mysql_query fail

1

I use the following code to manually insert new row to a table:

<?php
mysql_connect ("localhost", "marknaeg_felixz", "xxxxxx") or die ('I cannot connect to the database because: ' . mysql_error());
mysql_select_db ("marknaeg_felixz");
echo mysql_query (
 'INSERT INTO categories
 VALUES (NULL, "link", "icon", "caption", "description", "sound")'
);
?>

Which works perfectly, but when I want to call that from AS

 function addCategory($link, $icon, $caption, $description, $sound) {
  return mysql_query (
   'INSERT INTO categories
   VALUES (NULL, $link, $icon, $caption, $description, $sound)'
  );
 }


connection.connect(gateway);
connection.call("DataBase.addCategory", responder, "link", "icon", "caption", "description", "sound");

I get false.