A Norristown man is accused of stealing more than $775 million from his employer over eight of the 13 years he worked there. 71-year-old William Barnes was Finance Director for the Valley Forge Convention and Visitors Bureau from 1996 until early last year. He was responsible for paying the nonprofit organization’s bills. An accounting firm hired to review the records after his retirement last year found numerous discrepancies and missing funds and referred the case to the Montgomery County District Attorney’s office. Investigators found that he wrote 293 unauthorized and forged checks to himself and covered up the thefts by altering computer records and other financial records. He said he used most of the money to pay child and spousal support. The bureau gets its funding mainly from memberships and a room tax paid by visitors staying in Montgomery County hotels. It was a county agency until 1999, when it became a private nonprofit.