Fortran: What does it mean: CALL XY(a,20,&50)

From: Katrin Scholz (kascho_at_katrinscholz.de)
Date: 01/31/05 

Date: 31 Jan 2005 02:25:47 -0800

Hello,

i've got a question concerning fortran77.

There's a subrouting call like this:

------------------
CALL XY (a,20,&50)
        ...
        ...
        ...

50 c='no'

------------------

      SUBROUTINE XY (IWERT,K,*)
      INTEGER*4 IWERT
       CALL AB(19,20,J)
       IF((J.LE.0).OR.(J.GT.K)) RETURN 1
       CALL CD(IWERT,J)
      RETURN
      END

----------------

Does it call the "50" and pass the value to the subrouting? Something
like indirect addressing?

What happend if there's something like this:

------------------------
      CALL XY (a,20,&60)
        ...
        ...
        ...

60 CALL color(red)

------------------

      SUBROUTINE XY (IWERT,K,*)
      INTEGER*4 IWERT
       CALL AB(19,20,J)
       IF((J.LE.0).OR.(J.GT.K)) RETURN 1
       CALL CD(IWERT,J)
      RETURN
      END

----------------

Do i pass the second subroutine to the first one? And when will it be
called - the second one? Before or after the CALL XY(a,20,&60)?

I hope you could help me a little bit?

Bye, Katrin