C # file download progress and speed

Visual Studio 2005 + WINXP SP2

Using system;
Using system. Collections. Generic;
Using system. componentmodel;
Using system. Data;
Using system. drawing;
Using system. text;
Using system. Windows. forms;
Using system. IO;
Using Microsoft. Win32;
Using system. runtime. interopservices;
Using system. net;
Using system. net. Sockets;

Namespace commonlibrary
{
Public partial class form1: Form
{
Private webrequest httprequest;
Private webresponse httpresponse;
Private byte [] buffer;
Private thread downloadthread;
Stream ns;
Private string filename = @ "D: \ hello1.mp3 ";
Private filestream FS;
Private long length;
Private long downlength = 0;
Private long lastlength = 0;
Public Delegate void updatedata (string value); // sets the delegate to update the main interface
Private int totalseconds = 0; // total time used
Private updatedata uidel ;//
Public form1 ()
{
Initializecomponent ();
Buffer = new byte [4096];

}

Private void button#click (Object sender, eventargs E)
{
Httprequest = webrequest. Create (this. textbox1.text );
Httpresponse = httprequest. getresponse ();
// MessageBox. Show (httpresponse. contentlength. tostring ());
Length = httpresponse. contentlength;
This. progressbar1.maximum = (INT) length;
This. progressbar1.minimum = 0;
Downloadthread = new thread (New threadstart (downloadfile ));
// Showthread = new thread (New threadstart (show ));
FS = new filestream (filename, filemode. openorcreate, fileaccess. Write );
Downloadthread. Start ();
This. timer1.enabled = true;
// Showthread. Start ();
}
Private void downloadfile ()
{

NS = httpresponse. getresponsestream ();

Int I;
Uidel = new updatedata (updateui );
While (I = NS. Read (buffer, 0, buffer. Length)> 0)
{

Downlength + = I;
String value = downlength. tostring ();
This. Invoke (uidel, value );
FS. Write (buffer, 0, I );
}
MessageBox. Show (" Download Completed ");
This. timer1.enabled = false;
This. label3.text = (length/(1024 * totalseconds) + "kb/s ";
}
/* Private void show ()
{
Uidel = new updatedata (updateui );
Int value = 0;
While (value <= 100)
{
This. progressbar1.value = value;
Value ++;
}
}*/
Void updateui (string value)
{
This. label1.text = value;
This. progressbar1.value = int32.parse (value );
}

Private void timereffectick (Object sender, eventargs E)
{
This. label2.text = (downlength-lastlength)/1024) + "kb/s ";
Lastlength = downlength;
Totalseconds ++;
}
}
}