private void mnuMainClearClipboard_Click(object sender, EventArgs e)
{
//clear copied files in clipboard
if (GlobalSetting.StringClipboard.Count > 0)
{
GlobalSetting.StringClipboard = new StringCollection();
Clipboard.Clear();
DisplayTextMessage(GlobalSetting.LangPack.Items["frmMain._ClearClipboard"], 1000);
}
}