Drawing Curves like Spline chart

programming flash
1

I have five dots(MovieClips) in my stage. I want to draw a curve which should touch all the five dots. The x position of dots are incremented by 50 px and y position is random.

I can do this using lineTo. But it has not got any curve effect.

Here is the code using lineTo

_root.createEmptyMovieClip("circle",1);
with (_root.circle) {
        clear();
        lineStyle(4,0x0000FF,100);
        moveTo(this.points_mc["Circ_mc"+0]._x,this.points_mc["Circ_mc"+0]._y);
        for (var i:Number = 0; i<5; i++) {
            lineTo(this.points_mc["Circ_mc"+i]._x,this.points_mc["Circ_mc"+i]._y);
            moveTo(this.points_mc["Circ_mc"+i]._x,this.points_mc["Circ_mc"+i]._y);
        }
}

I tried curveTo to achieve this. But it is not working.

Please let me know if I am not clear.