Replace emoticons with smileys

<?PHP
// this is the funktion
function smile_replace($text) {
 // Here is the array with the smilies, it can be extended
 $smileys = array (
 ':)' =>'<img src="smileys/smile.gif" alt="Smile" width="20" height="20" border="0">',
 ':o' => '<img src="smileys/dazed.gif" alt="Dazed" width="20" height="20" border="0">',
 ';)' => '<img src="smileys/wink.gif" alt="Wink" width="20" height="20" border="0">',
 ':(' => '<img src="smileys/sad.gif" alt="Sad" width="20" height="20" border="0">',
 ':angel:' => '<img src="smileys/angel.gif" alt="Angel" width="20" height="20" border="0">',
 ':devil:' => '<img src="smileys/devil.gif" alt="Devil" width="20" height="20" border="0">',
 ':up:' => '<img src="smileys/up.gif" alt="Thumb up" width="20" height="20" border="0">'
 );
 // Here are the smileys replaced
 $text = str_replace (array_keys($smileys), array_values($smileys), $text);
 return $text;
}
// This is an example text
$mytext = ":up: This is a simple guestbook entry with smileys :) ;) :angel:";
// and so we use the function
echo smile_replace($mytext);
?>