//</snippet1>
private void AuthenticateWithUserName()
{
//<snippet2>
CalculatorClient client = new CalculatorClient("default");
//</snippet2>
//<snippet3>
client.ClientCredentials.UserName.Password = ReturnPassword();
//</snippet3>
//<snippet4>
client.ClientCredentials.UserName.UserName = ReturnUsername();
//</snippet4>
//<snippet5>
double value1 = client.Add(100, 15.99);
//</snippet5>
//<snippet6>
client.Close();
//</snippet6>
}