Форуми / Cotonti / Support / icon-comment.gif (delete bug)

I have a strange bug on me site :
When i wanne edit in the functions.php this line

$res = "<a href=\"$url#comments\" class=\"comments_link\"><img src=\"skins/".$usr['skin']."/img/system/icon-comment.gif\" alt=\"\" />";
to this

$res = "<a href=\"$url#comments\" class=\"comments_link\">";

and refesh the page i get Page can't be found error