Does the opposite of eaclass. That is, given a eA Job class, it returns which is the corresponding RO class number.
A gender is required because both Bard and Dancers share the same eA Job value (EAJ_BARDDANCER), if it isn't given, the
gender of the executing player is taken (if there's no player running the script, male will be used by default).
The command returns -1 when there isn't a valid class to represent the required job (for example, if you try to get the
baby version of a Taekwon class).

set @eac, eaclass();
//Check if class is already rebirth
if (@eac&EAJL_UPPER) {
mes "You look strong.";
close;
}
set @eac, roclass(@eac|EAJL_UPPER);
//Check if class has a rebirth version
if (@eac != -1) {
mes "Bet you can't wait to become a "+jobname(@eac)+"!";
close;
}