Score counting problem

Guys, i am having a nightmare of a problem with score counting in my game.
I have made it so when my character hits the coin it disappears (that part works) but it should also make the score say '1'.
Instead is says '_level0.score' (i have set it to 0 in the actions of the frame "_root.score = 0;" but that doesn't seem to work)

The coins actions also say to add 1 point to the score when the character hit the coin

Actionscript Code:

onClipEvent (enterFrame) {
    if (this.hitTest(_root.char_blue)) {
        this.gotoAndStop(2);
        _root.score += 1;
    }
}

but instead it says "NaN"

The text's instance name is "score"

Here is my game if would like to take a look!
http://jhtechno.com/projects/flash/M...ROBLEM_CS4.fla