ELSEIFDIF        ELSE With IFDIF                                    Directive

  ELSEIFDIF <argument1>, <argument2>

     This directive is the same as an ELSE followed by an IFDIF. (IFDIF is
     satified if the two arguments are different.) It is used to start a
     nested conditional block. For example:

                        IF NUMBER EQ 5
                           add ax,3
                        ELSEIFDIF NAME1, NAME2
                           add bx,2
                        ELSE
                           add cx,1
                        ENDIF

       Notes:     See ELSEIF and IFDIF for more information.