Question: Metro-Goldwyn-Mayer contract star Arlene Dahl starred in the film "Ambush" in 1950, which was based on a story of the same name written by who?

Context paragraphs:
Laraine Day: Laraine Day (October 13, 1920 – November 10, 2007) was an American actress and a former Metro-Goldwyn-Mayer contract star.  As a leading lady in her day, she was paired opposite major film stars including Lana Turner, Cary Grant, and John Wayne.

Eileen Percy: Eileen Percy (21 August 1900 – 29 July 1973) was an Irish actress of the silent era.  She appeared in 68 films between 1917 and 1933.  She was born in Belfast and died in Los Angeles, California.  Her remains are buried at Chapel of the Pines Crematory.  She was married to songwriter Harry Ruby.  She was portrayed by Arlene Dahl in "Three Little Words" (1950).

Manuel Conde: Manuel Conde (born Manuel Urbano; October 9, 1915 in Daet, Camarines Norte – August 11, 1985) was a Filipino actor, director and producer.  As an actor, he also used the screen name Juan Urbano during the 1930s aside from his more popular screen name.  His first film was "Mahiwagang Biyolin" in 1935.  He made almost three dozen films under LVN Pictures as a contract star.  He later put up his own movie company, Manuel Conde Pictures, in 1947 which produced classic films, notably the Juan Tamad series (Si Juan Tamad (1947), Si Juan Daldal (Anak ni Juan Tamad) (1948), Juan Tamad Goes to Congress (1959), Juan Tamad Goes to Society (1960), Si Juan Tamad At Juan Masipag sa Pulitikang Walang Hanggan (1963)).  Other movies Conde produced, directed and/or starred were Vende Cristo (1948), Prinsipe Paris (1949), Krus Na Kawayan (1956), Siete Infantes de Lara (1950) and its re-make in 1973, Molave (1961) and the internationally acclaimed Genghis Khan (1950).

The Outriders: The Outriders is a 1950 Technicolor Western film starring Joel McCrea and Arlene Dahl.

Ambush (1950 film): Ambush is a 1950 western film directed by Sam Wood and starring Robert Taylor, John Hodiak and Arlene Dahl.  This was the last film directed by Sam Wood.  The plot is based on the serial story "Ambush" by Luke Short in "The Saturday Evening Post" (25 Dec 1948–12 Feb 1949).

Diana Lewis: Diana Lewis (September 18, 1919 – January 18, 1997) was an American film actress and a Metro-Goldwyn-Mayer contract star.

Arlene Dahl: Arlene Carol Dahl (born August 11, 1925) is an American actress and former Metro-Goldwyn-Mayer contract star, who achieved notability during the 1950s.  She has three children, the eldest of whom is actor Lorenzo Lamas.

Jamaica Run: Jamaica Run is a 1953 adventure-drama concerning ownership of an old estate set on the island in the Caribbean.  It was directed by Lewis R. Foster and starred Ray Milland, Arlene Dahl and Wendell Corey.

A Southern Yankee: A Southern Yankee (1948) is an American comedy film, directed by Edward Sedgwick, starring Red Skelton and Arlene Dahl, and released by Metro-Goldwyn-Mayer.  It is also known as The Spy.

Three Little Words (film): Three Little Words is a 1950 American musical film biography of the Tin Pan Alley songwriting partnership of Kalmar and Ruby and stars Fred Astaire as lyricist Bert Kalmar, Red Skelton as composer Harry Ruby, along with Vera-Ellen and Arlene Dahl as their wives, with Debbie Reynolds in a small but notable role as singer Helen Kane.  The film, released by Metro-Goldwyn-Mayer, was written by Academy Award winning screenwriter George Wells, directed by Richard Thorpe and produced by Jack Cummings.  Harry Ruby served as a consultant on the project, and appears in a cameo role as a baseball catcher.  It was the third in a series of MGM biopics about Broadway composers; it was preceded by "Till the Clouds Roll By" (Jerome Kern, 1946) and "Words and Music" (Rodgers and Hart, 1948) and followed by "Deep in My Heart" (Sigmund Romberg, 1954).

Supporting paragraphs: Ambush (1950 film) Arlene Dahl
Answer: Luke Short