ho risolto cosi:

codice:
<html>
    <head>
    <script language="javascript" type="text/javascript" src="tinymce/jscripts/tiny_mce/tiny_mce.js"></script>

        <script language="javascript" type="text/javascript">

 tinyMCE.init({
    theme : "advanced",
    mode : "none",
    theme_advanced_toolbar_location : "top",
    theme_advanced_buttons1 : "bold,italic,underline,strikethrough,separator,"
    + "justifyleft,justifycenter,justifyright,justifyfull,formatselect,"
    + "bullist,numlist,outdent,indent",
    theme_advanced_buttons2 : "link,unlink,anchor,image,separator,"
    +"undo,redo,cleanup,code,separator,sub,sup,charmap",
    theme_advanced_buttons3 : "",
    height:"300px",
    strict_loading_mode: false
  });

            function init_rte()    {
                tinyMCE.execCommand('mceAddControl', false, "Editor");      
            }
        </script>
    </head>
    <body>
        <form>
            <textarea id="Editor">Test</textarea>
        </form>
        Click me
    </body>
</html>