Question about loadmovie action

Scenario:

-I have an external movie called "dumovie.swf"

-In another movie, I have a button with the following code:

===========================
on(press){
_level0.loadMovie("dumovie.swf");
}

==========================
.... and sure enough the movie "dumovie.swf" loads in place. However, if i use the code :
_level1.loadMovie("dumovie.swf");

instead(i changed _level0 to _level1) it doesnt work. I dont know what's going on, why can't I load the "dumovie.swf" movie on a level of "1" instead of "0"???

thanksNadvance

use loadMovieNum to load movies into different levels