ADAS Subroutine b2sort

       SUBROUTINE B2SORT(XA,YA,N)                                       
C
       IMPLICIT REAL*8(A-H,O-Z)                                         
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: B2SORT *********************
C
C PURPOSE : TO SORT AN ARRAY SO THAT XA IS IN INCREASING ORDER        
C
C  N.B.  INPUT VALUES ARE ALTERED BY THIS ROUTINE !!!!
C
C  INPUT
C      XA(I)=X-VALUES
C      YA(I)=Y-VALUES
C      N=NUMBER OF VALUES
C  OUTPUT
C      XA(I)=SORTED X-VALUES
C      YA(I)=SORTED Y-VALUES
C
C NOTES: THIS ROUTINE IS NOT YET PROPERLY ANNOTATED
C
C UNIX-IDL PORT:
C
C VERSION: 1.1                          DATE: 06-03-96
C MODIFIED: TIM HAMMOND (TESSELLA SUPPORT SERVICES PLC)
C               - PUT UNDER S.C.C.S. CONTROL
C
C-----------------------------------------------------------------------
C
      INTEGER             N
      REAL*8              XA(10),      YA(10)