error in connect to xmpp(openfire) server using java

I am new in xmpp. For a whole day i am stuck in connecting my xmpp server(openfire version 3.9.3) by java. I am using smack(version 4.0.7) library. Here is simple code...

            ConnectionConfiguration config =new ConnectionConfiguration("servername",5223);
            XMPPTCPConnection connection = new XMPPTCPConnection(config);
                // Connect to the server
                try {
                        connection.connect();
                    connection.login("username", "password");

                    }  catch (IOException e) {
                        e.printStackTrace();
                    } catch (XMPPException e) {
                        e.printStackTrace();
                    } catch (SmackException e) {
                        e.printStackTrace();
                    } 

But when i run this code this errors is showing ...

org.jivesoftware.smack.SmackException$NoResponseException
at org.jivesoftware.smack.XMPPConnection.throwConnectionExceptionOrNoResponse(XMPPConnection.java:548)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.throwConnectionExceptionOrNoResponse(XMPPTCPConnection.java:867)
at org.jivesoftware.smack.tcp.PacketReader.startup(PacketReader.java:113)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.initConnection(XMPPTCPConnection.java:482)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.connectUsingConfiguration(XMPPTCPConnection.java:440)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.connectInternal(XMPPTCPConnection.java:811)
at org.jivesoftware.smack.XMPPConnection.connect(XMPPConnection.java:396)
at test.third.<init>(third.java:19)
at test.third.main(third.java:34)

There may be a silly mistake and easy solution, i googled but but somehow i am not getting the right solution.please help me. Thanks in advance