A lot of you seem to be confusing the words "gender" and "sex". Yes, I know that the word "gender" has become,for some extraordinary reason,popular for describing a person's SEX, but that doesn't make it right and proper . Go on --be different !! Refer to peoples' sex, as it does on Birth Certificates,and leave GENDER to grammarians ! Unless the word SEX is un-feminist, or "dirty",or something ? Beats me !