Cool i watched a video and i learned a little bit and i have its work !!
function planeEnter ( theVehicle, seat, jacked ) -- when someone enters a vehicle
local id = getElementModel ( theVehicle ) -- get the model ID of the vehicle
if id == 519 or id == 577 then -- if theVehicle is either Shamal or AT-400
local vehicleName = getVehicleName ( theVehicle ) -- get the name of theVehicle
outputChatBox ( "Someone stole a " .. vehicleName .. "!" ) -- announce that someone stole the plane
end
end
-- add the event handler to the event
addEventHandler ( "onPlayerVehicleEnter", getRootElement(), planeEnter )