In the querySample() code, how does VS know what the Contact data type is? I get this error message:

Error    1    The type or namespace name 'Contact' could not be found (are you missing a using directive or an assembly reference?)   

I added WSDL to the web references and named it sForce.And I am using the following libraries.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Services.Protocols;
using Program.sforce;

namespace Program
{
class Program
{
static public SforceService binding;

static void Main(string[] args)
{


Console.Write("Enter username: ");
string username = Console.ReadLine();
Console.Write("Enter password: ");
string password = Console.ReadLine();

// Create a service object
binding = new SforceService();

// Timeout after a minute
binding.Timeout = 60000;

// Try logging in
LoginResult lr;
try
{
Console.WriteLine("LOGGING IN NOW...");
lr = binding.login(username, password);
}
// ApiFault is a proxy stub generated from the WSDL contract when
// the web service was imported
catch (SoapException e)
{
// Write the fault code to the console
Console.WriteLine(e.Code);

// Write the fault message to the console
Console.WriteLine("An unexpected error has occurred: " + e.Message);

// Write the stack trace to the console
Console.WriteLine(e.StackTrace);
}

Console.ReadLine();
}

private void querySample()
{
//The results will be placed in qr
QueryResult qr = null;

//We are going to increase our return batch size to 250 items
//Setting is a recommendation only, different batch sizes may
//be returned depending on data, to keep performance optimized.
binding.QueryOptionsValue = new QueryOptions();
binding.QueryOptionsValue.batchSize = 250;
binding.QueryOptionsValue.batchSizeSpecified = true;

try
{
qr = binding.query("select FirstName, LastName from Contact");
bool done = false;
if (qr.size > 0)
{
Console.WriteLine("Logged-in user can see "
+ qr.records.Length + " contact records.");
while (!done)
{
Console.WriteLine("");
for (int i = 0; i < qr.records.Length; i++)
{
Contact con = (Contact)qr.records[i];
string fName = con.FirstName;
string lName = con.LastName;
if (fName == null)
Console.WriteLine("Contact " + (i + 1) + ": " + lName);
else
Console.WriteLine("Contact " + (i + 1) + ": " + fName
+ " " + lName);
}
if (qr.done)
{
done = true;
}
else
{
qr = binding.queryMore(qr.queryLocator);
}
}
}
else
{
Console.WriteLine("No records found.");
}
}
catch (Exception ex)
{
Console.WriteLine("\nFailed to execute query succesfully," +
"error message was: \n{0}", ex.Message);
}
Console.WriteLine("\n\nHit enter to exit...");
Console.ReadLine();
}
}
}