get image on url, replace and reload in runtime

Hello I'm trying to get an image from a url, for that I have made this script in C # .. working properly .. corutine as I use to validate the download, I can not do it in update, what I need is that if I overwrite the .jpg file on the local disk, web, or unity do reload and show the new img.

I am new to scripting, so I urge you stick the complete code if anyone knows how.

thanks.

     //antonio Cotos
     using UnityEngine;
     using System.Collections;
     
     // Get the content by url
     
     
     public class www : MonoBehaviour {
     
     public string url = "http://192.168.0.15/demo/img/1.png";
     
     
     
     
         IEnumerator Start() {
               // Start a download of the given URL
              WWW www = new WWW (url);
             
              // Wait for download to complete
              yield return www;
              
     
              // assign texture
              Renderer renderer = GetComponent<Renderer>();
              renderer.material.mainTexture = www.texture;
             }
                   
      }