How to Get Text from Online File .text

I assume that your problem is the HTML text showed in the notify icon text. Probably the web site (asap.eb2a.com...) does not allow unknown agents, so it returns some message to inform you or the a.text file contains HTML and JavaScript code. The first problem can be bypassed by adding a header to the WebClient object to mask your call as if it is coming from a web browser:

Get.Headers.Add ("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");

The loops created using the goto/label construct can be replaced by a System.Timers.Timer class. This will also simplify your code:

• create the WebClient object to call the uri
• create a variable to preserve the downloaded text
• create a timer object and bind the Elapsed event, that is called every 100 milliseconds
• in the timer Elapsed event download the data from the site using the WebClient.DownloadString method
• compare the already saved text with the newly downloaded string: if their are different, then show the notify icon

The implementation looks like this:

WebClient Get = new WebClient();
// identify your self as a web browser
Get.Headers.Add ("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");
Uri uri = Uri("http://asap.eb2a.com/a.text");
string contentToShow = String.Empty;
// timer for the repetitive task called every nnn milliseconds
const long refreshIntervalInMilliseconds = 100;
System.Timers.Timer timer = new System.Timers.Timer(refreshIntervalInMilliseconds);
timer.Elapsed += (s, e) =>
{
    Console.WriteLine(String.Format("{0} Fetching data from: {1}", DateTime.Now, uri));
    try
    {           
        var result = Get.DownloadString(uri);
        if (result != contentToShow)
        {
            contentToShow = result;
            notifyIcon1.Visible = true;
            notifyIcon1.BalloonTipText = contentToShow;
            notifyIcon1.BalloonTipTitle = "We Notify You";
            notifyIcon1.ShowBalloonTip(150);
        }
    }
    catch (Exception exception)
    {
        MessageBox.Show(string.Format("Error: {0}", exception.Message));
    }
};
// start the timer
timer.Start();