AC_ARG_WITH(system-zlib,
[AS_HELP_STRING([--with-system-zlib], [use installed libz])],
if test x$with_system_zlib = xyes ; then
AC_ARG_WITH(system-zlib,
[AS_HELP_STRING([--with-system-zlib], [use installed libz])],
if test x$with_system_zlib = xyes ; then