INT 15 - VMiX - "sys_clrwindow" - CLEAR WINDOW
	AH = 14h
	STACK:	WORD	top left corner of window (high byte = row, low = col)
		WORD	bottom right corner of window (high = row, low = col)
Return: AX = status (SYS_OK)
Note:	clears window to color set with "sys_setcolors" (AH=18h)
SeeAlso: AH=15h"VMiX",AH=16h"VMiX",AH=18h"VMiX",AH=1Fh"VMiX"
                                                                                

INT 15 - MultiDOS Plus - CHECK IF MultiDOS FOREGROUND OR BACKGROUND             
	AH = 14h
Return: AX = current state
	    0000h MultiDOS Plus command prompt is background task
	    0001h command prompt is foreground task
SeeAlso: AH=0Bh"MultiDOS"