How to post blog on twitter

See more:

C#

ASP

I want to post a blog or article on Twitter from my website.I have a consumer key and a secret key. When I request the access token at that time I'm getting an exception.

My code:

protected void Page_Load(object sender, EventArgs e)
    {
       
    }
    protected void btnsave_Click(object sender, EventArgs e)
    {
        var consumerKey = "aB7dtwUzfX6DYoEjRBWTQg";//ConfigurationManager.AppSettings["ConsumerKey"];

        var consumerSecret = "ByLUPqPJ8lFAjAvZwmcD5tx7lvwmyGoJJ4BAPvcJI"; //ConfigurationManager.AppSettings["ConsumerSecret"];

        OAuthTokens accessToken = new OAuthTokens();
        //accessToken.AccessToken = "290554160-qiq29iDg7kEEAMWgJ4u9Wm8zlG9pXNrjjn8XPDOP";
        //accessToken.AccessTokenSecret = "YiBaNbeU6w3z1Hj0DN1rjX45e6DAh9wEinM6qhPE34I";
        accessToken.ConsumerKey = consumerKey;
        accessToken.ConsumerSecret = consumerSecret;
        


        TwitterStatus TweetStatus = new TwitterStatus(accessToken);
        TweetStatus.Update(txtpost.Text);
        Response.Redirect("http://twitter.com/#!/klsh123");

    }
    protected void btnauth_Click(object sender, EventArgs e)
    {
        var consumerKey = "aB7dtwUzfX6DYoEjRBWTQg";//ConfigurationManager.AppSettings["ConsumerKey"];

        var consumerSecret = "ByLUPqPJ8lFAjAvZwmcD5tx7lvwmyGoJJ4BAPvcJI";
    
    //If User is not valid user
    if (Request.QueryString["oauth_token"] == null)
    {
        //Get Request Token
        OAuthTokenResponse RequestToken = OAuthUtility.GetRequestToken(consumerKey, consumerSecret);
                                                

        // Redirect User to Requested Token
        Response.Redirect("http://twitter.com/oauth/authorize"+RequestToken.Token);
    }
    else
    {
        //For Valid User
        string Oauth_Token = Request.QueryString["oauth_token"].ToString();
        var accessToken = OAuthUtility.GetAccessToken(consumerKey,
                                              consumerSecret,
                                              Oauth_Token);

        //lblMessage.Text = "Hello + accessToken.ScreenName";

        //lblMessage.Text += "<br /> Token: " + accessToken.Token;
        //lblMessage.Text += "<br /> TokenSecret: " + accessToken.TokenSecret;
        //lblMessage.Text += "<br /> UserId: " + accessToken.UserId;
    } 
}