Email Question - Adding multiple email addresses - beginner

Question

I have a form that once submitted will send an email to predetermined users. I am at a point now that I need to send it to multiple users. I can't figure out how I can add an additional user in the TO: field.
I have tried concating :
affectTO = lab.concat(";").concat(manager);system print out of affectTO :
[email protected];[email protected] is what I need(and I know that the emails are not null) but this throws this error:
javax.servlet.ServletException: Illegal semicolon, not in groupand just using '+' doesnt work either
affectTO = lab + manager;I get this error message:
javax.servlet.ServletException: Illegal character in domainSo how can I have multiple email addresses in the TO field?
Any suggestions would be appreciated.
Thanks,
Crystal
oot.user.user userIDs =(oot.user.user)session.getAttribute("userIDs");
            String labID =(String)userIDs.getLabID();
        oot.user.lab.lab labEmail = labDB.labEmailInfo(newID, labID);
            String lab =(String)labEmail.getLabEmail();
            String managerID = (String)userIDs.getManagerID();
        oot.user.manager.manager managerEmail = managerDB.managerEmailInfo(newID, managerID);
            String manager = (String)managerEmail.getManagerEmail();
            //affectTO = lab + manager;
            //affectTO = lab.concat(";").concat(manager);
try {
             if(affectTO != null) {
                sendAffectNotice(smtpServer, affectTO, affectFROM, affectSUBJECT, affectCONTENT);
        } catch (Exception e) {
            throw new ServletException(e.getMessage());
        }

Answer 1

Sample....
public void sendMessage(Vector to, Vector cc, Vector bcc,
    String from, String subject, String body)
    throws Exception {       
        // Create the new message
        MimeMessage msg = new MimeMessage(session);
            // Parse and set the recipient addresses
            if (to != null) {
                Iterator i = to.iterator();
                while(i.hasNext()){
                    String t = (String) i.next();
                    logger.debug("parsing the to address " + t);
                    Address[] toAddresses = InternetAddress.parse(t);
                    msg.addRecipients(Message.RecipientType.TO,toAddresses);
// other code............
            }