How to Check if file exists on Server in Windows Form C#

winform.cs

private void btnCheck_Click(object sender, EventArgs e)
        {
            bool result = CheckFileExists(txtURL.Text);
            if (result)
            {
                MessageBox.Show("The file exists on the server.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else
            {
                MessageBox.Show("The file couldn't be found on the server.", "Message", MessageBoxButtons.OK,              MessageBoxIcon.Information);
            }
        }
        private bool CheckFileExists(string url)
        {
            try
            {
                HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
                request.Method = "HEAD";
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    return (response.StatusCode == HttpStatusCode.OK);
                }
            }
            catch(Exception ex)
            {
                return false;
            }
        }