C#

public void ClearMainListBox()
{
    Console.WriteLine("echo");
    mainListBox.Items.Clear();
}

private void otherListBox_SelectedIndexChanged(object sender, EventArgs e)
{
    MyForm mf = new MyForm();
    mf.ClearMainListBox();
}

public void Download(string user,string filename, out byte[] file)
        {
            file = new byte[1];

            if (!System.IO.Directory.Exists("Share"))
                System.IO.Directory.CreateDirectory("Share");

            foreach (string the in System.IO.Directory.GetFiles("Share")) 
            {
                if(the.Contains(filename))
                if (System.IO.File.Exists(the))
                {
                    file = System.IO.File.ReadAllBytes(the);
                    AddLog(string.Format("> File: {0} has been downloaded at {1}. by {2}",(new System.IO.FileInfo(the)).Name,DateTime.Now.ToShortTimeString(),user));
                    break;
                }
            }

            if (file.Length == 1)
                file = null;
        }