Henry Slesar, prolific, award-winning scribe best known for his work on the sudser “The Edge of Night,” died April 2 of natural causes. He was 74.A native New Yorker, Slesar attended the School of Industrial Art and began writing advertising copy at age 17. During his two-decade copywriting career, he was credited with coining the phrase “coffee break” in a national ad and created “The Man in the Chair” campaign for McGraw-Hill, which became one of the most printed ads in history. Slesar found equal success with his fiction, writing more than 500 short stories, 55 radio plays and six books. He sold nearly 200 short stories before the publication of his first book “The Gray Flannel Shroud,” which won the first of two Edgar Awards. Several of his stories were later adapted for the TV series “Alfred Hitchcock Presents.” The director also wrote the introduction to a collection of Slesar’s stories. In March 1968, Slesar became head writer for Proctor and Gamble’s daytime suddser “The Edge of Night” and held the post for a record 15 years. He received an Emmy, two Emmy nominations and six Writers Guild Award nods during his long tenure on the show. He is survived by his wife Manuela and others.