void CmdDeleteWord()
{
int pos = WordForward(cursor);
if (pos == -1)
return;
string k = text.ToString(cursor, pos - cursor);
if (last_handler == CmdDeleteWord)
kill_buffer = kill_buffer + k;
else
kill_buffer = k;
text.Remove(cursor, pos - cursor);
ComputeRendered();
RenderAfter(cursor);
}