dragging Image Sequence

This script, sequence of images.

While playing a sequence of images, Since the previous frame or move the frame.

Movement of the frame, Want by dragging.

What should I do?

var frames : Texture2D[]; var framesPerSecond = 10.0;

     function Update () {
     
     var index : int = Time.time * framesPerSecond;
         index = index % frames.Length;
         renderer.material.mainTexture = frames[index];
 }