Save jpg on project folder instead of show to user

// here is the code

protected void ExportToImage(object sender, EventArgs e)
    {
        string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
        byte[] bytes = Convert.FromBase64String(base64);
        Response.Clear();
        Response.ContentType = "image/png";
        Response.AddHeader("Content-Disposition", "attachment; filename=HTML.png");
        Response.Buffer = true;
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.BinaryWrite(bytes);
        Response.End();
    }