ADAS Subroutine xxeiam

       subroutine xxeiam( esym  , xsym )
c-----------------------------------------------------------------------
c
c  ****************** fortran77 subroutine: xxeiam *********************
c
c  purpose:  Routine to return the atomic mass number for a given element
c            symbol esym.  
c
c  calling program: gapecf
c
c
c  subroutine:
c
c  input : (i*4)  esym   = the symbol of the element required (note that
c                          case is unimportant as the uppercase of the
c                          input value is always taken).
c  output: (i*4)  xsym   = the float value of the atomic mass of the element.
c                          If the symbol is not recognised then the value
c                          of xsym returned is zero.
c
c routines:
c          routine    source    brief description
c          ------------------------------------------------------------
c          xxcase     adas      converts a string to upper or lower case
c
c author:  Hugh Summers, University of Strathclyde
c          JA7.08
c          tel. 0141-548-4196
c
c date:    15/01/02
c
c update:
c
c-----------------------------------------------------------------------
      CHARACTER*(*)       ESYM
      REAL*8              XSYM