Airport officials are telling passengers to get to the airport earlier thsn usual starting tomorrow because of tighter security checks going into effect.Their suggestion is for pasengers domestic flights to arrive two hours before the scheduled flight and even earlier for international fights.The tighter security checks mean a lot more people will have to take off their shoes and belts or open their carry-on bags.An airport spokesman says the new measures will be temprapry and will last less than a month.Airports in Beijing,Guangzhou and Hangzhou began the tighter security checks on Tuesday.