using System;

using System.Collections.Specialized;

using System.Net;

​

using (WebClient client = new WebClient())

{

  byte[] response = client.UploadValues("https://textita.com/text", new NameValueCollection() {

    { "phone", "9087938341" },

    { "message", "Sample SMS Text" },

    { "key", "textita" },

  });

​

  string result = System.Text.Encoding.UTF8.GetString(response);

}

​