Zimbabwe's President Robert Mugabe has said he will quit after 33 years in power if he loses Wednesday's election."If you lose you must surrender," the Zanu-PF party leader said.His remarks came as Prime Minister Morgan Tsvangirai's Movement for Democratic Change (MDC) party accused Zanu-PF of doctoring the voters' roll.Zanu-PF denied the accusation, saying it was the responsibility of the electoral commission, which released the roll only on the eve of polls.The BBC's Farayi Mungazi in the capital, Harare, has seen the document and says it features the names of thousands of dead people.Some names also appear twice or three times with variations to their ID numbers or home address.Mr Mugabe will be facing Mr Tsvangirai in the presidential ballot.The two long-time rivals have been sharing power since 2009, under a deal brokered by the regional bloc to end conflict that marred elections in 2008.