Eddie Murphy has been added to the growing list of donors who have opened their checkbooks to the striking actors' union relief fund. Yesterday, the "Nutty Professor" star made a $100,000 contribution to the Screen Actors Guild Foundation, its executive director, Marcia Smith, told the Associated Press. Members of SAG and the American Federation of Television & Radio Artists began their walkout against the advertising industry on May 1, in protest of pay rates for actors in commercials. Other high-profile actors who have donated to the SAG Foundation strike relief fund include Nicolas Cage ($200,000) and Harrison Ford, Helen Hunt, Kevin Spacey and Bruce Willis ($100,000 each). The strike is the first major Hollywood labor dispute in a dozen years. It affects only radio and TV ads, not movies or TV series, though there are rumblings that such a walkout could occur next year.