On my yahoo account, how do i change the settings so that my last name doesn't appear on my emails?

i tried going to my account settings and changed it to just show the first initial atleast since it is a required field, but then when i saved the changes, the changes didn%26#039;t take place!! my whole last name was still showing!! :( help...|||http://us.f319.mail.yahoo.com/ym/Prefere鈥?/a>





In mail, go to options, then General Preferences.