Move the cursor to coordinates (y,x) and delete the character
    on the specified window. The mvdelch function acts on the stdscr
    window.
    Format
      #include  <curses.h>
      int mvdelch  (int y, int x);
      int mvwdelch  (WINDOW *win, int y, int x);
1 – Arguments
 win
    A pointer to the window.
 y
    A window coordinate.
 x
    A window coordinate.
2 – Description
    Each of the following characters on the same line shifts to the
    left, and the last character becomes blank.
3 – Return Values
    OK                 Indicates success.
    ERR                Indicates that deleting the character would
                       cause the screen to scroll illegally. For more
                       information, see the scrollok function.