First heard on network radio in 1948, Yours Truly, Johnny Dollar chronicled the adventures of freelance insurance investigator Johnny Dollar, ''the man with the action-packed expense account.'' For fourteen years it was one of the most popular detective shows on the air, lasting until the final days of network radio drama in 1962. Each story started with a phone call from an insurance executive calling on Johnny Dollar to investigate an unusual claim. His investigations usually required him to travel to distant locales and often involved murder. Over the years, many actors portrayed Johnny Dollar, but in 1955 Bob Bailey took over as the series was switching to a new dynamic format.