# - - - u s a g e
def usage ( *L ):
"""Write a usage message and stop.
[ L is a list of strings ->
sys.stderr +:= (usage message) + (joined elements of L)
stop execution ]
"""
print >>sys.stderr, "*** Usage:"
print >>sys.stderr, "*** conjd NNNNNNN.NN..."
print >>sys.stderr, "*** where NNNNNNN.NN is the Julian date."
print >>sys.stderr, "*** Error: %s" % "".join(L)
raise SystemExit