 is opened or closed
(<b><tt>GSDLL_DEVICE</tt></b>), when the window should be redrawn
(<b><tt>GSDLL_SYNC</tt></b> or <b><tt>GSDLL_PAGE</tt></b>) or when the
bitmap size changes (<b><tt>GSDLL_SIZE</tt></b>).
Note that more than one <b><tt>os2dll</tt></b> device may be opened.

<h3><a name="OS2_bmp"></a><b><tt>gsdll_get_bitmap()</tt></b></h3>

<blockquote>
<b><tt>gsdll_get_bitmap()</tt></b> returns a pointer to a bitmap in BMP
format.  The <b><tt>os2dll</tt></b> device draws into this bitmap.

<blockquote>
<