qamar, there's a few ways to do this one way is to load your sections into different levels, something like this...
b.t.w just using PHP to make it easier to follow
or you could load your sections into movie clips and make them invisible until needed...
var x = 100;
// remove 1 from x
// x = the level to load your movie into
loadMovie ("http://www.pathtoyourmovie.com/blah.swf", x);
_root.moviePloy._visible = false;
// moviePloy = the name of the mc your loading into