Int 62 Fn 0074  u - Fgdriver V4.02 - "fg_mousebut" - Get Mouse Button Pre  [V]

   AX = 0074h
   CX = mouse button (1 = left press, 2 = right press, 3 = middle press,
         -1=left release, -2=right release, -3=middle release)
   ES:BX -> variable pointer record (see #3161)

Return: variables updated

Notes: the FGDRIVER functions are rearranged with each major release, but
     their parameters do not change (see #3145 at AX=0000h)
   This function returns the count of presses or releases since the last
     call to this function; if the count is zero, row and column will
     also be zero

See Also: AX=0075h,AX=0077h,AX=007Ah

Format of FGDRIVER MOUSEBUT variable pointer record:
Offset Size    Description (Table 3161)
 00h   WORD    segment of WORD buffer for press/release count
 02h   WORD    offset of WORD buffer for press/release count
 04h   WORD    segment of WORD buffer for screen space col of last press/rls
 06h   WORD    offset of WORD buffer for screen space col of last press/rels
 08h   WORD    segment of WORD buffer for screen space row of last press/rls
 0Ah   WORD    offset of WORD buffer for screen space row of last press/rls