Score - changing frames once it reaches a certain score

[suzierthanyou]

I have a game where there is a spaceship shooting at bubbles. The score goes up by 10 each time it hits.

How can I make it so that when the score reaches a certain point, something new happens? (Aka. a gotoandplay so-and-so?)

Here's my code:

var DARTSPEED:Number = 20;
var BUBBLESPEED:Number = 5;
var STAGEWIDTH:Number = 500;
var total:Number = new Number ();

total = 0;

var DARTSTART:Number = dart._y;		// save dart start position

// define the bubbles' behavior
bubble1.onEnterFrame = 
bubble2.onEnterFrame = 
bubble3.onEnterFrame = 
bubble4.onEnterFrame = 
bubble5.onEnterFrame = function() {
   // while bubble is still onstage:
   if (this._x < STAGEWIDTH) {
      this._x += BUBBLESPEED;
      // easier to check here against dart rather than vice versa
      // MUST check if in frame 1 or command will be executed repeatedly
      if (this.hitTest(dart) && this._currentframe==1) {
         this.gotoAndPlay("explode");
		 _root.total = _root.total + 10;
	  }
   // when bubble goes offstage:
   } else {
      // the following three lines of code add randomness to the balloons' appearance
      // reposition on left, between 0 and 50 pixels to the left of the stage
      this._x = 0-this._width - Math.random()*50;
      // randomly move up or down, up to 20 pixels
      this._y += -20 + Math.random()*40;
      // randomly change size +/- up to 10%
      this._xscale = this._yscale = -10 + this._xscale + Math.random()*20;
      // set back to normal (unexploded) view
      this.gotoAndStop(1);
   }
}

// define the shooter behavior
shooter.onPress = function() {
   this.startDrag(false, 0, this._y, STAGEWIDTH-this._width, this._y);
   this.onMouseMove = function() {
      dart._x = this._x + 4;
   }
}

shooter.onRelease = shooter.onReleaseOutside = function() {
   this.stopDrag();
   delete this.onMouseMove;

   dart.onEnterFrame = function() {
      // if the dart is still onstage, move it upwards a defined number of pixels per frame
      if (this._y > 0-dart._height) {
         this._y -= DARTSPEED;
      // if it has gone off the top of the stage, reset it to its original position
	  // and stop the enterFrame to wait for the next release of shooter
      } else {
         this._y = DARTSTART;
         delete this.onEnterFrame;
      }
   }
}

I'd also like to say thank you to everyone who's helped me thus far. I hope I'm not annoying you!