it depends on time of year and how certain u have to be of getting to hanoi on a certain date - if youi need to be in hanoi to catch an international flight on Xate, best to book. also it depnds on what other flights you need - if you are getting an air pass\, need to book asap as seats for the relevant class of travel are limited.
you can check flight availability online for laos airlines and that will give you some idea; vietnams airlines should have their lonline booking service up sometime soon.
#2 basejump has been a member since 14/11/2008. Posts: 30