Ti è sufficiente incapsulare il contenuto all'interno di script in cdata



codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Documento senza titolo</title>
<script type="text/javascript">
 <![CDATA[
function MM_swapImgRestore() { //v3.0
      ....
}
function MM_preloadImages() { //v3.0
      ....
}

function MM_findObj(n, d) { //v4.01
     ....
}

function MM_swapImage() { //v3.0
     .....
}
 ]]>
</script>
</head>

<body onload="MM_preloadImages('immagini/tasto_glossario_2012_mo.jpg')">
    ......
</body>
</html>