Editing tables sorted using joins

I have a table and I want to number the records from 1 to whatever by gender (ie: all boys from 1 to the number of boys and then all girls from 1 to the number of girls). The gender of the entries is in another table. So I joined the tables to sort by gender. At that point I was going to number the records but it won't let me edit. Is there some way to do this?

Post up your table layouts:

Example:
tblMain
MainID - Autonumber
fieldname1 - Text - 10 - allowzerolength
fieldname2 - Text - 10 - allowzerolength
sexid - number - long

tblSex
sexid - autonumber
sex - text - 10 - allowzerolength


Vince