“Nobody puts Baby in a corner.” Anyone glued to movies in 1987 will remember the line from the runaway hit dance romance “Dirty Dancing,” which was written and co-produced by Eleanor Bergstein. Three months ahead of its London opening, Bergstein’s own stage version has clocked up an advance in excess of £4.5 million ($8.3 million) and has just announced a six-month extension to the opening booking period.The show uses songs from the bestselling movie soundtrack plus “Save the Last Dance for Me” by the Drifters and Marvin Gaye’s “Stubborn Kinda Fella.” Bergstein wanted them for the movie but wasn’t able to secure the rights back then. Originally workshopped in New York in 2001 under the auspices of the Dodgers, it was picked up by Australia’s Jacobsen Co. It opened in Sydney in November 2004 in a fiercely competitive season where it was expected to be the underdog against “The Lion King” and “We Will Rock You,” but sold more than 1 million tickets over 500 perfs. The German premiere in Munich (co-produced with Stage Entertainment) broke box office records with 290,000 advance sales. Insiders suggest the production cleaves closely to the film script right down to there being 75 separate scenes. Kevin Jacobsen is looking at a North American opening, possibly Toronto, prior to Broadway.