twitter api in c# to update twitter status [Resolved]

Hi all,

I am using TwitterApi to post twits on twitter.

but It's not working. It throws TwitterApiException

my code is

 try
           {
               a.AuthenticateWith(ConsumerKey, ConsumerSecretKey, TokenKey, TokenSecret);
               string text = "hello twitter";
               a.Update(text);            
               
           }
           catch (TwitterAPIException ex)
           {
               Label1.Text = ex.Message;
           }

whats going wrong?
or any other way to do this?

Happy Programming!!
Rohi [Resolved]