Category: <b>BIOS</b>
<br>Flags: callout or callback (usually hooked rather than called)<p>
<pre><b>INT 15 - OS HOOK - DEVICE CLOSE</b>

	AH = 81h
	BX = device ID
	CX = process ID
	CF clear
Return: CF clear if successful
	    AH = 00h
	CF set on error
	    AH = status (see <a href=../../it/96/4.html>#00496</a>)
Note:	this function should be hooked by a multitasker which wishes to keep
	  track of device ownership; the default BIOS handler merely returns
	  successfully
SeeAlso: AH=80h,AH=82h
</pre>