Don died at his home in Sag Harbor, New York on Saturday (14Jul12) at the age of 91.
He found success in the 1950s as a TV writer and went on to enjoy a career spanning more than five decades.
Don penned scripts for popular U.S. shows such as Wanted: Dead or Alive, The Fugitive, The Man from U.N.C.L.E. and The Untouchables, and went on to serve as producer on series including Tarzan, Medical Center and Trapper John, M.D. in the 1980s.
He adopted Christie as a child when he wed the beauty's mother Marjorie Hudson, and she took her stepdad's last name.