Delete the line at the current position of the cursor. The
    deleteln function acts on the stdscr window.
    Format
      #include  <curses.h>
      int deleteln();
      int wdeleteln  (WINDOW *win);
1 – Argument
 win
    A pointer to the window.
2 – Description
    Every line below the deleted line moves up, and the bottom line
    becomes blank. The current (y,x) coordinates of the cursor remain
    unchanged.
3 – Return Values
    OK                 Indicates success.
    ERR                Indicates an error.