RAT_RBHD() Determines if the mouse right button is currently
 depressed

 Returns
 <lDepressed> => mouse right button is currently
 depressed

 Syntax
 RAT_RBHD()

 Description
 Determines if the mouse right button is currently
 depressed

 Examples
  if RAT_RBHD()

    ?"Mouse right button depressed NOW"

  endif

 Notes:
 This is different from the event function
 RAT_ERBHD(). RAT_ERBHD(<n>) watches the mouse for <n> seconds,
 and if the mouse remains depressed for the full time, then it is
 considered to be HELD DOWN. RAT_RBHD() on the other hand, only
 checks for the mouse button being depressed RIGHT NOW.
 RAT_ERBHD() calls RAT_RBHD() repetitively.

 Source: S_MOUSE.ASM