if and else statement HELP ANYONE!!!

i have this code for email notification... if the Session["empmail"].ToString() is null i want to skip the send mail notification...
can u pls help me how to do this....


here's my mail notification code.
MailMessage msg = new MailMessage("123@13456.com", Session["empmail"].ToString(), "SUbject", "Body Message");
        SmtpClient client = new SmtpClient("MY IP ADDR");
        client.Send(msg);  
        client.Timeout = 500;
        client.Credentials = CredentialCache.DefaultNetworkCredentials;


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