FUNCTION ch_kadd2list(iobsnmb) 1
#if defined (DOC)
*
***s/r ch_kadd2list  - add new observation descriptors into list NVNUMB
*
*Author  : Y. Yang   June 2004
*Revision:
*          Y.J. Rochon ARQX/MSC May 2005
*            - Indentation alignment
*
*Purpose:
*
*   Check whether or not the obs descriptor read from the namelist is 
*   already in NVNUMB.  If not, add it to the end of nvnumb list 
*   (the first place that has 0)
*
*Arguments
*
*   input:
*         iobsnmb: desciptor to be added
*   output
*         ch_kadd2list: the position at which the descriptor is found or added
*                    in NVNUMB
*
#endif
C
      IMPLICIT NONE
*implicits
#include "comnumbr.cdk"
#include "comdim.cdk"
#include "comchem.cdk"
#include "comlun.cdk"
*
      INTEGER ch_kadd2list
      INTEGER iobsnmb, II, JJ
C
      ch_kadd2list = 0
      II = -1
C
      if (iobsnmb .ne. 0) then
         DO II = 1,jpnbrelem
            if (NVNUMB(II) .ne. 0 ) then
                if (iobsnmb .eq. NVNUMB(II)) go to 500
            else
                NVNUMB(II) = iobsnmb
                go to 500
            endif
         ENDDO
  500    continue
      endif
C
      ch_kadd2list = ii
C
      RETURN
      END