How to send and receive message using agsXMPP SDK and openfire Asp.net

I am developing chat application using openfire server and xmpp protocol with agsXMPP SDK and asp.net, i have done login process and get all registered user into list successfully, i have OnMessage method to send message but i do not know that where to call this method.

I do not want to use MatriX XMPP SDK because it is paid. i am able to send message but not able to retrieve message, below code i am using for retrieve messages but is not working and where to call this method

private void xmppClient_OnMessage(object sender, MailMessageEventArgs e)

    {
        Response.Write(string.Format("OnMessage from {0}", e.Message.From));
        Response.Write(string.Format("Body {0}", e.Message.Body));

    }
please help me