private void ToolStripMenuItemMakeEmptyFromCurrentClick(object sender, EventArgs e)
{
if (ContinueNewOrExit())
{
bool isAlternateVisible = SubtitleListview1.IsAlternateTextColumnVisible;
// NOTE: new Subtitle(_subtitle) will generate new ID for original subtitle.
// which is wrong new id should be generate only for new empty-translation.
_subtitleAlternate = new Subtitle(_subtitle);
_subtitleAlternateFileName = null;
int oldIndex = FirstSelectedIndex;
if (oldIndex < 0)
oldIndex = 0;