4KB only

[=?Utf-8?B?SnVzdCBjbG9zZSB5b3VyIGV5ZXMgYW5kIHNlZQ==]

Hello All
I had tried downloading files from an ftp server but it is only download 4kb
all the time, I think this is due to buffer size,but I am not sure
here is my code, plz help

FileStream outputStream = new FileStream(@"D:\temp\" +
listBox1.SelectedItem.ToString(), FileMode.Create);
ftp = (FtpWebRequest)FtpWebRequest.Create(new
Uri("ftp://ftp.AnyServerName.com/"));
ftp.Method = WebRequestMethods.Ftp.DownloadFile;
ftp.UseBinary = true;
ftp.UsePassive = true;
ftp.Credentials = new NetworkCredential("username", "password");
//I had used the following 2 lines to come over proxy
authentication
ftp.Proxy = WebProxy.GetDefaultProxy();
ftp.Proxy.Credentials = CredentialCache.DefaultCredentials;
//
FtpWebResponse response = (FtpWebResponse)ftp.GetResponse();
Stream str = response.GetResponseStream();

int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];

readCount = str.Read(buffer, 0, bufferSize);
while (readCount 0)
{
outputStream.Write(buffer, 0, readCount);
readCount = str.Read(buffer, 0, bufferSize);
}

str.Close();
outputStream.Close();
response.Close();
MessageBox.Show("Done");