user cannot edit the page I have given the marketing role the 'create new', 'edit own' and 'delete own' permission for the Article content type however when I log in with that account the 'edit' button doesn't appear on the article page so that user cannot modify the page]1
Use this code may be it helpful 

if ($query == $user-&gt;uid &amp;&amp; arg(0) == 'node' &amp;&amp; is_numeric(arg(1)) &amp;&amp; arg(2)== 'edit' ){

$query_path= db_query("select n.nid from {node} n
where n.nid =$nid")-&gt;FetchField();
 drupal_goto('node/'.$query_path);
}


place uid with your role id