INT 2A - NETWORK - EXECUTE NetBIOS REQUEST

	AH = 04h
	AL = error retry
	    00h automatically retry request on errors 09h, 12h, and 21h
		  (see #03248 at INT 5C"NetBIOS")
	    01h no retry
	    02h ???
	ES:BX -> Network Control Block (see #03249 at INT 5C"NetBIOS")
Return: AX = 0000h if successful
	AH = 01h on error
	    AL = error code
Notes:	invokes either INT 5B or INT 5C as appropriate
	supported by PC LAN Program, LANtastic, LAN Manager, NetWare, 10NET,
	  etc.
	NetWare 2.15 NetBIOS emulator returns CF clear if successful, CF set
	  on error
	PC LAN Program defines any non-zero return value in AH as an error
	  indicator for subfunction 00h, and any non-zero return value in AX
	  as an error indicator for subfunction 01h
SeeAlso: AH=00h,AH=01h,AX=0500h,INT 5B"Extended NetBIOS",INT 5C"NetBIOS"