Salve a Tutti!!!

Ho un problema con questa pagina asp.... solo su firefox, su IE funziona benissimo.
in pratica...
ho un tendina (select) con (onChange--> richiama una funzione)
nella funzione a seconda di cosa ho selezionato
vengono aperti o chiusi dei DIV (style display: block/none)
su firefox è tutto morto... non si muove una foglia
ecco il codice:
codice:
<script language="vbscript" type="text/vbscript">
function FUNZ1()
if document.getElementById("tipo").getAttribute("value")="tin" OR document.getElementById("tipo").getAttribute("value")="cop" then
document.getElementById("openapp").style.display="none"
document.getElementById("opentde").style.display="none"
end if
if document.getElementById("tipo").getAttribute("value")="tde" then
document.getElementById("openapp").style.display="none"
document.getElementById("opentde").style.display="block"
end if
if document.getElementById("tipo").getAttribute("value")="app" then
document.getElementById("opentde").style.display="none"
document.getElementById("openapp").style.display="block"
end if
end function
</script>
<script language="vbscript" type="text/vbscript">
function FUNZ2()
document.getElementById("openapp").style.display="none"
document.getElementById("opentde").style.display="none"
end function
</script>
...
response.write("<form name='form1' method='post'>")
...
response.write("<tr><td align='center' colspan='2'>
<u>Tipologia</u></td></tr>")
response.write("<tr><td colspan='2' align='right'><select name='tipo' Id='tipo' onChange='FUNZ1()'>")
response.write("<option></option>")
response.write("<option value='tin'>Indeterminato</option>")
response.write("<option value='tde'>Determinato</option>")
response.write("<option value='app'>Apprendistato</option>")
response.write("<option value='cop'>CO. Prog.</option>")
response.write("</select></td></tr>")
....
response.write("<tr><td align='center' colspan='2'><u>Inquadramento</u></td></tr>")
response.write("<tr><td width='50%'>Qualifica</td><td><input type='text' name='qual' /></td></tr>")
response.write("<tr><td width='50%'>Livello</td><td><input type='text' name='live' /></td></tr>")
...
response.write(" <div name='opentde' Id='opentde' style='display: none; margin-left: 0px;'>")
response.write("<table width='300'>")
response.write("<tr><td width='50%'>Data Cessazione</td><td><input type='text' name='datacess' /></td></tr>")
response.write("<tr><td width='50%'>Durata</td><td><input type='text' name='durata' /></td></tr>")
response.write("<tr><td width='50%'>Motivazione</td><td><input type='text' name='moti' /></td></tr>")
response.write("</table>")
response.write(" </div>")
response.write(" <div name='openapp' Id='openapp' style='display: none; margin-left: 0px;'>")
response.write("<table width='300'>")
response.write("<tr><td width='50%'>Data Cessazione</td><td><input type='text' name='datacess' /></td></tr>")
response.write("<tr><td width='50%'>Durata</td><td><input type='text' name='durata' /></td></tr>")
response.write("<tr><td width='50%'>Primo Stato</td><td><input type='text' name='1stato' /></td></tr>")
response.write("<tr><td width='50%'>Secondo Stato</td><td><input type='text' name='2stato' /></td></tr>")
response.write("<tr><td width='50%'>Terzo Stato</td><td><input type='text' name='3stato' /></td></tr>")
response.write("<tr><td width='50%'>Quarto Stato</td><td><input type='text' name='4stato' /></td></tr>")
response.write("</table>")
response.write(" </div>")
response.write("<table width='300'>")
response.write("<tr><td width='50%'>In Corso</td><td><input type='checkbox' name='incorso' value='1' checked /></td></tr>")
response.write("<tr><td align='right'><input type='submit' value='Salva' /></td><td><input type='reset' value='Annulla' onClick='FUNZ2()' /></td></tr>")
response.write("</table>")
response.write("</form>")