Nero Burning Order?

my nero version is 6.3.1.10
I want to know how nero determine the ordering of file to burn?
e.g. file 1, 2, 3, 4
but when it starting burning, i find it burn file in order of 3,2,1,4 ... how it organize the file and directory order on burn process
it is dvd profile

@ bobochan
I thought you could drag and drop them where you want them to be, but you could try adding track numbers to the front of the titles(01Title1, 02Title2). Just make sure you use a zero before the single digits('01') if you have 10 or more titles on one disc to maintain their alpha-numeric order.