setInterval method

programming flash
1

var nAb:Number=10;
var arrX:Array=new Array(); var arrY:Array=new Array();
var direct:Number;
var Vx:Number; var Vy:Number;
var initx:Number=215; var inity:Number=210;
var vmax:Number=10; var vmin:Number=2;

for (var i:Number = 1; i <= nAb; i++)
{
duplicateMovieClip(ab_mc, “ab”+i, this.getNextHighestDepth());
_root[“ab”+i]._x = initx;
_root[“ab”+i]._y = inity;

_root["ab"+i].onPress = function(){
    this.unloadMovie();
}

Vx=Math.round(Math.random()* (vmax-vmin)+vmin);
Vy=Math.round(Math.random()* (vmax-vmin)+vmin);
direct= Math.round(Math.random()* 3);

    switch(direct)
{
    case 0 :
    arrX*=Vx;
            arrY*=Vy; 
    break;
    
    case 1 :
    arrX*=Vx;
    arrY*=Vy* -1; 
    break;
    
    case 2 :
    arrX*=Vx* -1;  
    arrY*=Vy;
    break;
    
    case 3 :
    arrX*=Vx* -1;
    arrY*=Vy* -1;
    break;
}

}

onEnterFrame = function(){

    for (var i:Number = 1; i &lt;=nAb; i++){
        
            _root["ab"+i]._x +=arrX*;
            _root["ab"+i]._y +=arrY*;
            
            if(_root["ab"+i]._x &gt;= Stage.width-23  ||  _root["ab" + i]._x &lt;= 23 || _root["ab" + i]._y &gt;= Stage.height-17 || _root["ab" + i]._y &lt;= 23)
                {                        
                    arrX* *= -1;
                    arrY* *= -1;
                    
                }
            if(_root["ab" + i]._x ==initx || _root["ab" + i]._y ==inity)
               {
                   _root["ab" + i].unloadMovie();
                }
    }

}

Hey guys! I have this code and i want to use setInterval (2 seconds) ( + clearInterval methods) and “game over” after 20 seconds
So can someone help me?! :S