How to connect to Team Foundation Server (TFS) using C#.NET

using Microsoft.TeamFoundation.Client;
using Microsoft.TeamFoundation.WorkItemTracking.Client;

//Declare Variables
private NetworkCredential networkCredential = new NetworkCredential("enter here User Name", "enter here password", "enter here domian");
private Uri uri = new Uri("enter here TFS URL");
string projectName="enter here TFS prject name";
string worktemType = "enter here Work Item Type";

//Set Authentication To TFS
TeamFoundationServer teamFoundationServer = new TeamFoundationServer(uri.AbsoluteUri, networkCredential);
teamFoundationServer.Authenticate();
//Add Work Item
WorkItemStore wis = (WorkItemStore)teamFoundationServer.GetService(typeof(WorkItemStore));
Project tfsProject = wis.Projects[projectName];
WorkItemType wiType = tfsProject.WorkItemTypes[workItemType];
WorkItem workItem = new WorkItem(wiType);
workItem.Title = "Test Work Item";
workItem.Description = "Work Item Description";
workItem.Save();