ADAS Subroutine i4eiss

      FUNCTION I4EISS( CHR )
C---------------------------------------------------------------------
C                                                                       ********
C  ****************** FORTRAN 77 FUNCTION: I4EISS ********************  ********
C
C  PURPOSE: RETURNS DECIMAL INDEX OF AN ORBITAL GIVEN IN THE EISSNER
C           HEXADECIMAL CHARACTER FORM.
C
C  CALLING PROGRAM: VARIOUS
C
C  SUBROUTINE:
C
C  INPUT  :  (C*1)   CHR    = HEX. ORBITAL CHARACTER (EISSNER)
C  OUTPUT :  (I*4)   I4EISS = DECIMAL ORBITAL INDEX (1 - 61)
C
C            (I*4)   I      = GENERAL INDEX
C            (C*1)   CHRA() = EISSNER HEXADECIMAL ORBITAL LIST
C
C  ROUTINES: NONE
C
C  AUTHOR:  H. P. SUMMERS, UNIVERSITY OF STRATHCLYDE
C           JA8.08
C           TEL. 0141-553-4196
C
C  DATE:    04/06/96
C
C UNIX-IDL PORT:
C	   WILLIAM OSBORN, TESSELLA SUPPORT SERVICES PLC.
C
C DATE:    20TH AUGUST 1996
C
C VERSION: 1.1				DATE: 20-08-96
C MODIFIED: WILLIAM OSBORN
C	    - FIRST VERSION. SET DEFAULT VALUE OF I4EISS TO ZERO 
C VERSION: 1.2				DATE: 19-02-03
C MODIFIED: H.P. SUMMERS - EXTENDED RANGE 
C-------------------------------------------------------------------------------
      CHARACTER           CHR