$WP5="/u/wp/shbin/cvt51";
    $WP8="/u/wp8/shbin10/cvt";
    $CVT= defined(-e '/u/wp/shbin/cvt51') ? $WP5 : $WP8;
   system ("$CVT $TMP1 -o $TMP2 asci >/dev/nul </dev/null");