Why will a car not start after sitting a while?

http://www.autozone.com/servlet/UiBroker?UseCase=S001&UserAction=viewSimpleDiagInfo&Parameters=info Could be moisture in the lines from old gas or the gas began to break down, depends on how old gas is if thiers moisture in there now try product called dry gas it bonds to water and carries it through engine with fuel to be burn or expelled