import flash.geom.Point;

 import flash.display.MovieClip;

 import flash.display.Graphics;

 function drawDashed(mc:Sprite,p1:Point,p2:Point,length:Number=5,gap:Number=5):void

 {

     var max:Number = Point.distance(p1,p2);

     var l:Number = 0;

     var p3:Point;

     var p4:Point;

     while(l<max)

     {

         p3 = Point.interpolate(p2,p1,l/max);

         l+=length;

         if(l>max)l=max

         p4 = Point.interpolate(p2,p1,l/max);

         mc.graphics.lineStyle(1,0xff00ff,1)

            mc.graphics.moveTo(p3.x,p3.y)

         mc.graphics.lineTo(p4.x,p4.y)

         l+=gap;

     }

 }

 var mc:MovieClip=new MovieClip();

 addChild(mc);

 drawDashed(mc,new Point(100,100),new Point(500,100),5,5);