* )
dnl AC_MSG_ERROR([the `--with-x-toolkit' option is supposed to have a value
dnl which is `yes', `no', `lucid', `athena', `motif' or `open-look'.])
-AC_MSG_ERROR([`--with-x-toolkit=$withval' is invalid\;
+AC_MSG_ERROR([`--with-x-toolkit=$withval' is invalid;
this option's value should be `yes', `no', `lucid', `athena', `motif' or `gtk'.
-Currently, `yes' and `gtk', and `athena' and `lucid' are synonyms.])
+`yes' and `gtk' are synonyms. `athena' and `lucid' are synonyms.])
;;
esac
with_x_toolkit=$val