
      docspec="${1}"
      docname="`basename "${docspec}"`"
      label="${2}"
      if test ! -n "${docname}"; then
         if test -n "${docspec}"; then
            echo >&2 "${HTX_SCRIPT}: no document name given: ${docspec}"
         else
            echo >&2 "${HTX_SCRIPT}: no document name given"
         fi
         exit 1
      fi
      done=''
      if test ! "${HTX_WHERE}" = 'r'; then
         if path="`expr "//${docspec}" : '//\(.*\)/.*'`"; then :; else
            path="${HTX_PATH-`${HTX_DIR}/htxpath`}"
         fi
         doc="`IFS=':'; for dir in ${path}; do doc="${dir:-.}/${docname}"
            (cd "${doc}.htx" 1>/dev/null 2>/dev/null) && echo "${doc}" && break
         done`"
         if test -n "${doc}"; then
            if test -n "${label}"; then
               eds='s%^<  *\([^ ][^ ]*\)  *\('"${label}"'\) *$%\1#xref_\2%p
                    t done
                    b
                    :done
                    q'
            else
               eds='s%^T  *\([^ ][^ ]*\).*$%\1#xref_%p'
            fi
            ifile="${doc}.htx/htx.index"
            if test -f "${ifile}" -a -r "${ifile}"; then
               filefrg="`sed -n "${eds}" "${ifile}"`"
            else
               echo >&2 \
               "${HTX_SCRIPT}: warning - document ${doc} has no index file"
               filefrg="`${HTX_DIR}/creindex "${doc}" | sed -n "${eds}"`"
            fi
            case "${doc}" in [!/]*) doc="`pwd`/${doc}";; esac
            if test -n "${filefrg}"; then
               echo "${doc}.htx/${filefrg}"
            elif test ! -n "${label}"; then
               echo "${doc}.htx/${docname}.html"
            else
               echo >&2 \
"${HTX_SCRIPT}: cannot find label \"${label}\" in document ${docname}"
               exit 1
            fi
            done='1'
         fi
      fi
      if test ! -n "${done}" -a ! "${HTX_WHERE}" = 'l'; then
         HTX_SERVER="${HTX_SERVER-http://star-www.rl.ac.uk/cgi-bin/htxserver}"
         echo "${HTX_SERVER}/${docname}.htx/${docname}.html?xref_${label}"
      fi         
