RAT_RIGHTB() Determines if the right mouse button has been
 pressed

 Returns
 <lHasBeenPressed> => right mouse button has been
 pressed

 Syntax
 RAT_RIGHTB()

 Description
 This returns .t. if the right button has been pressed
 since last call to this function. Row and column are recorded
 for reference by rat_rowr() and rat_colr().

 Examples
  if rat_rightb()

    ?"While you were out:"

    ?"Left button was depressed at"

    ??rat_rowr(),rat_colr()

  endif

 Notes:
 This is different from RAT_RBHD() in that RAT_RBHD()
 is a 'right now' function - determining if the button IS
 depressed, whereas this function determines if the button HAS
 been depressed.

 Source: S_MOUSE.ASM