British actress LIZ DAWN is quitting popular soap opera Coronation Street to battle lung disease. Dawn, who has played Vera Duckworth in the Manchester-based soap for 34 years, will leave the ITV show before Christmas (07). The 68-year-old actress has the lung disease emphysema and has told programme producers she is too sick to continue. Dawn says, "It's been an amazing 34 years. I'd like to thank everyone for what has been the best time of my life." Coronation Street is Britain's longest-running television soap opera and is aired in many countries worldwide, including Canada, Australia, Belgium and Holland.