Execute Container.SetSortMethod automatically

I want that the songs of any album should be displayed in sorted order based on Track Number not Title.
For this In "MyMusicNav.xml" I have written :

<onload>Container.SetSortMethod(7)</onload>

but it does not work, since first time the Albums are going to be displayed and for Albums, sort by Track number is meaningless.

And upon clicking any album the songs are displayed which should be sorted by Track number but that time the <onload> even is not fired so Container.SetSortMethod(7) is not executed.

When I write same thing on click of a button then it sorts the songs based on Track number.
But I want to happen it automatically means I don't want to provide a button for this.