bene....
grazie al prezioso aiuto di r@avem@ster abbiamo fatto la versione java delle select dinamiche.

la servlet e il web xml sono quelli indicati prima. Il main.jsp va modificato nel seguente modo:

codice:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    
<% 



List provincia = new ArrayList();


try{
	
	Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    String filename = "C:\\Documents and Settings\\minicgag\\Desktop\\miei scripts\\Database Venditori\\Database_Venditori.mdb";
    //String filename = "D:\\JONAS_4_8_4\\webapps\\autoload\\callc\\registrochiamate.mdb";
    String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=";
    database+= filename.trim() + ";DriverID=22;READONLY=true}"; // add on to the end 
    // now we can get the connection from the DriverManager
    Connection con = DriverManager.getConnection( database ,"",""); 
    Statement s = con.createStatement();
    
    String query1 = "select * from provincia where attivo = 'si'";
    
    s.execute(query1);
    ResultSet rs = s.getResultSet();
    if(rs!=null){
	    while(rs.next()){
	    	provincia.add(rs.getString(1));
	    	provincia.add(rs.getString(2));
	    	
	    }
    }
    	
	
    
    con.close(); // close the Connection to let the database know we're done with it
    s.close();
	
    
    
	
	

}
catch(Exception e){
	e.printStackTrace();
}
finally{
	try {
		
	} 
	catch (Exception e) {
		e.printStackTrace();
	}
}
%>



<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@page import = "java.util.ArrayList" %>
<%@page import = "java.util.List" %>
<%@page import = "java.sql.*" %>



<script language="javascript" type="text/javascript">
<!--
var http = createRequestObject(); 
var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 : null; 

function createRequestObject() { 
     var ro; 
     var browser = navigator.appName; 
     if(browser == "Microsoft Internet Explorer"){ 
          ro = new ActiveXObject("Microsoft.XMLHTTP"); 
     }else{ 
          ro = new XMLHttpRequest(); 
     } 
     return ro; 
} 

function addElement(ogg,val,text){ 
  var newOption; 
  newOption = document.createElement("option"); 
  newOption.value = val; 
  newOption.text = text; 
  ogg.add(newOption, where);     
} 

function removeElement(ogg){ 
  if(ogg.options.length > 0){ 
    while (ogg.options.length) { 
      ogg.remove(0); 
    }     
  } 
} 

function disabledElement(ogg,val){ 
  document.getElementById(ogg).disabled = val; 
} 

function loadingProvince(oggId){ 
  var id = document.getElementById(oggId).value; 
  http.open('GET','do.getComune?prov='+id, true); 
  http.onreadystatechange = getComune; 
  http.send(null);   
} 

function getComune(){ 
  var State = document.getElementById('l2'); 
  removeElement(State); 
  id = document.getElementById('Select_provincia').value; 
  if(id == 'sel'){ 
    disabledElement('l2',true); 
    addElement(State,'sel','Seleziona prima un Continente:'); 
  }else{ 
    if(http.readyState == 4){ 
      if (http.status == 200) { 
           var response = http.responseText; 
           document.getElementById("select2").innerHTML = response;
           
        
           disabledElement('l2',false); 
        } 
         
    }else{ 
      addElement(State,'sel','Loading...'); 
    } 
  } 
  
} 



//-->
</script>



</head>

            
    <form name="form">
    	<div id="content"> 
		  <div id="label1"> 
		    Select 1 
		  </div> 
		  <div id="select1"> 
		    <select id="Select_provincia" name="Select_provincia" onchange="loadingProvince('Select_provincia')" >
                    <%for(int i=0;i<provincia.size();i=i+2){ %>
                    <option <%if(provincia.get(i+1)=="Milano"){%> selected="selected" <%}%> value="<%=provincia.get(i) %>"><%=provincia.get(i+1) %></option>
                    <%} %>
                </select>
		  </div> 
		  <div id="label2"> 
		    Select 2 
		  </div> 
		  <div id="select2"> 
		    <select name="l2" id="l2" disabled> 
		    <option value="sel" selected="selected">Seleziona un comune:</option> 
		    </select>   
		  </div>   
		     
		</div> 
    	
    </form>
</body>
</html>

Spero di esservi stato di aiuto... per tutti quelli che come me, ci hanno sbattuto parecchio la testa