parm file, jc=exists
##  exists.xeq
##  Dr. Ferenc Nagy, http://alpha0.iki.kfki.hu/~nagyf/
##    Budapest, Hungary
setjcw cierror=0
continue
listf !file;$null
if cierror=907 then
  flyback
  setjcw !jc=0
else
  setjcw !jc=1
endif