codice:
<%
submit = request.serverVariables("REQUEST_METHOD") = "POST"
thisPage = request.serverVariables("PATH_INFO")

if submit then

  errore = false

  data1 = request.form("data1")
  data2 = request.form("data2")

    if not isDate(data1) then
    errore = true
    data1error = true
    end if

    if not isDate(data2) then
    errore = true
    data2error = true
    end if

   if not errore then
   ' qui fai le operazioni qualora le date sono corrette...
   end if

end if
%>
<form method="post" action="<%=thisPage%>">
Data 1 <input type="text" name="data1" value="<%=data1%>" /><% if data1error then %> <font color="red">V</font><% end if %>

Data 2 <input type="text" name="data2" value="<%=data2%>" /><% if data2error then %> <font color="red">V</font><% end if %>

<input type="submit" value="VAI" />
</form>