Depending on which function is used to open a window, the window's
attributes may be specified using tagitems, or a newwindow structure or an
extnewwindow structure.  in the code above, the window attributes are set
up with an array of TagItems:

    struct TagItem win_tags[] =
        {
        {WA_Left,       MY_WIN_LEFT},
        {WA_Top,        MY_WIN_TOP},
        {WA_Width,      MY_WIN_WIDTH},
        {WA_Height,     MY_WIN_HEIGHT},
        {WA_CloseGadget,TRUE},
        {WA_IDCMP,      IDCMP_CLOSEWINDOW},
        {TAG_DONE, NULL},
        };

These window attributes set the window's position (wa_left, wa_top) and
size (wa_width, wa_height), request a close gadget on the window
(wa_closegadget) and ask intuition to send a message whenever the user
activates the close gadget (wa_idcmp).

Throughout this chapter window attributes are referred to by their TagItem
ID name (the name is always prefixed with "WA_").  See the section below
on "window attributes" for a complete list.

    Old and New Flag Names.
    -----------------------
    The names used for IDCMP flags and window flags have been changed
    under Release 2.  IDCMP flag names are now preceded by "IDCMP_".
    Likewise window flag names are now preceded by "WFLG_".  The old
    names (and their new equivalents) are listed in
    <intuition/iobsolete.h>.  you may want to refer to this file if
    you are working with example code written for V34 and older versions
    of the OS.