Access denied on applet in broswer - fine in applet viewer

Question

I have written an applet that access a php file and sends a post message. I have tested the applet with the applet viewer and it succeeds each time. When I put the applet on a web page I get the following error:
access denied (java.net.SocketPermission libraries.cjt-design.com:80 connect,resolve)
Any help is appreciated.
The code is as follows:
               try {
                    message = code + "&" + toMessage + "&" + fromMessage + "&" + subjectMessage + "&" + bodyMessage;
                    URL url;
                    HttpURLConnection urlConn;
                    PrintWriter out;
                    url = new URL(target);
                    urlConn = (HttpURLConnection) url.openConnection();
                    urlConn.setRequestMethod("POST");
                    urlConn.setRequestProperty("Referer", "http://libraries.cjt-design.com/index.html");
                    urlConn.setDoOutput(true);
                    urlConn.setDoInput(true);
                    urlConn.setUseCaches(false);     
     out = new PrintWriter(urlConn.getOutputStream());
     out.print(message);
     out.close();
          InputStream is = urlConn.getInputStream();
          // any response?
          InputStreamReader isr = new InputStreamReader(is);
          BufferedReader br = new BufferedReader(isr);
                         String s = "";
                         String response = "";
          while ( (s = br.readLine()) != null)
                              response += s;
          is.close();
                    statusLabel.setText(response);
                    statusLabel.invalidate();
               } catch (Exception e) {
                    String error = e.getMessage();
                    jEditorPane1.setText(error);
                    error = "Server Exception Occurred - Please try again later.";
                    statusLabel.setText(error);
                    statusLabel.invalidate();
               }

Answer 1

1. Why does it work from the applet viewer and not
the webpage.Appletviewer is in effect a Java application so it runs using the Java application security manager which by default gives an application almost unlimited access to the machine it runs on.
Running an Applet from a Web page runs the Applet constrained by the Applet security manager. By default, the Applet security manager assumes that anything that is downloaded from the web is untrusted so severely limits what an Applet can do. A signed Applet is assumed to be trusted if the certificate chain points back to one of the certificate roots such as Verisign.
You can use self signing for test purposes and then a client will be asked whether or not he trusts the Applet.
2. How do I make the jar file signed?http://java.sun.com/docs/books/tutorial/jar/sign/signing.html
http://java.sun.com/j2se/1.5.0/docs/tooldocs/solaris/jarsigner.html
http://java.sun.com/developer/onlineTraining/Security/Fundamentals/magercises/Signtool/help.html