Create image in Flash, post to .NET (C#)

[rook14]

So I am trying to create an image in flash and post it to a .NET page so that it can be saved on the server. I am getting this error in the .NET page when I post: Invalid character in a Base-64 string

Any ideas? Thanks! I actually want to create a png but wanted to get it working with jpg first... (less moving parts)

private function createJpg():void {
            var image:BitmapData = new BitmapData(_png.width, _png.height);
            image.draw(_png);

            var enc:JPGEncoder = new JPGEncoder(85);
            var bytes:ByteArray = enc.encode(image);

            var base64:Base64Encoder = new Base64Encoder();
            base64.encodeBytes(bytes);

            var vars:URLVariables = new URLVariables();
            vars.imageData = base64;
            
            var url:URLRequest = new URLRequest("localhost:1497/Services/FamineUploadImage.ashx");
            url.data = vars;
            url.method = URLRequestMethod.POST;
            
            var loader:URLLoader = new URLLoader();
            loader.addEventListener(Event.COMPLETE, onSaveComplete);
            loader.addEventListener(IOErrorEvent.IO_ERROR, onSaveError);
            loader.load(url);
        }

.NET Page:

using System;
using System.Collections.Generic;
using System.Data.Linq;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Services;
using StructureMap;
using WorldVision.Data.Services;

namespace WorldVision.Website.Services
{
    /// <summary>
    /// Summary description for $codebehindclassname$
    /// </summary>
    [WebService(Namespace = "tempuri")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class FamineUploadImage : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            var data = context.Request.Form["imageData"];

            // THIS IS WHERE IT ERRORS!
            byte[] bytes = Convert.FromBase64String(data);

            // Write the jpeg to disk
            string path = context.Server.MapPath("~/Save.jpg");
            File.WriteAllBytes(path, bytes);

            // Clear the response and send a Flash variable back to the URL Loader
            context.Response.Clear();
            context.Response.ContentType = "text/plain";
            context.Response.Write("ok=ok");
            
        }
        

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}