important documents required for air travel??

location form south east Asia to any European country.

A Passport and a ticket will be handy :)
Check with the arriving country ((i.e. if you are travelling from Thailand to Ireland, call the Irish embassy in Thailand )) for relevant up to date information on visas & conditions of entry etc. Have your passport details at hand cos sometimes entry regulations differ from person to person and the authorities may be able to give more relevant information from viewing your details through your passport number
hope this helps, enjoy europe!! :)