salve a tutti

come faccio a rendere non intrusivo lo script $(document).ready(function(e) ??
ho provato a scriverlo su un file js e a invocarlo come gli altri
ma non mi funziona lo script
grazie mille

Codice PHP:
<!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" lang="it">
<
head>
  <
script language="javascript" src="prova.js" type="text/javascript"></script>
    <script language="javascript" src="msdropdown/jquery-1.2.6.pack.js" type="text/javascript"></script>
    <script language="javascript" src="msdropdown/dd.js" type="text/javascript"></script>
    <link rel="stylesheet" type="text/css" href="msdropdown/dd.css" />
<script>
$(document).ready(function(e) {
                            try {
                                MSDropDown.init();
                            } catch(e) {
                                alert(e);
                            }
                           }
                  )
</script>

</head>
<body>
<h1>Cambia stile</h1>
<select name="webmenu" id="webmenu" onchange="showValue(this.value)">
    <option value="Default" >Default</option>
    <option value="Firefox">Firefox</option>
    <option value="Safari" >Safari</option>
    <option value="Storic" >Storic</option>
</select>


</body>
</html>