C# OPEN FILE DIALOG BROWSE FILES

       copy and pest
      inside a method  eg button click
   private void button1_Click(object sender, EventArgs e)
        {
            DialogResult result=dialog.ShowDialog();
            if(result==DialogResult.OK)
            {
                buff=System.IO.File.ReadAllBytes(dialog.FileName);
                labelfilename.Text=dialog.FileName;
            }
        }

otherwise

OpenFileDialog dialog;       
 DialogResult result=dialog.ShowDialog();
            if(result==DialogResult.OK)
            {
                buff=System.IO.File.ReadAllBytes(dialog.FileName);
                labelfilename.Text=dialog.FileName;
            }