str_replace()

[Atari]

can someone please tell me how to replace for example 🙂 with smile.gif; I believe it's str_replace("🙂","smilies/smile.gif")
But where do I put this? It's used in a guestbookscript. Every piece of text that is get out of the mysql will be checked en replaced if necessary.

[stolzyboy]

<?
$stringfrommysql = str_replace(":)", "<img src=\"graphics/smily.gif\">", $stringfrommysql);
echo $stringfrommysql;
?>

[Pig]

Put where ever the displaying page is. Don't try to do it to the info in the database, but to the output instead.