Question about Transition Tutorial

I’m getting a weird error message when I test my button. Here is the code I’m using on my main buttons, substituting the section name of course.

code:

[color=blue]on (rollOver) {
this.gotoAndPlay(“over”);
}
on (rollOut) {
this.gotoAndPlay(“out”);
}
on (release) {
if (_root.currMovie == undefined) {
_root.currMovie = “extra”;
[color=slategray]//refer to _root[/color]
_root.contents.loadMovie(“extra.swf”);
} else if (_root.currMovie != “extra”) {
[color=slategray]//refer to _root[/color]
if (_root.contents._currentframe >= contents.midframe) {
_root.currMovie = “extra”;
[color=slategray]//refer to _root[/color]
_root.contents.play();
}
}
}[/color]

This is the error message I get.

Error opening URL “[file:///C|/Documents%20and%20Settings/HP%5FOwner/Desktop/KIM%20WEB%20backup%20may%207%202005/Main%20Sections/undefined.swf](file:///C|/Documents%20and%20Settings/HP%5FOwner/Desktop/KIM%20WEB%20backup%20may%207%202005/Main%20Sections/undefined.swf)”

Does any one have any Ideas on why it’s looking for ‘undefined.swf’?