Download an image with JS?

Question

I´m trying to download an image from an URL with Javascript using socket.
My first problem was separating the header from the body. I do it by reading line by line and if the line starts with "\n" then it seams to be the body.
A problem with this is that it´s very very slow. Reading a 1x1 pixel png takes 5-10 seconds.
The stranger thing is that I can´t write the content to file. I can write a string to a file, but not the body of the image, toString() doesn´t seem to help.
Anyone with experience or advice?
var img_data = "";
var line;
var body_start = false;
var conn = new Socket;
if (conn.open ("www.test.com:80", "BINARY")) {
var request = "GET /phoenix/images/5_topnavlogo.jpg HTTP/1.1\n" +
  "Host: www.test.com\n" +
  "User-Agent: InDesign ExtendScript\n" +
  "Accept: text/xml,text/*,*/*\n" +
  "Accept-Encoding:\n" +
  "Content-Length: 0\r\n" +
  "Content-Type: application/x-www-form-urlencoded\r\n" +
  "Connection: keep-alive\n" +
  "Accept-Language: *\n" +
  "Accept-Charset: utf-8\n" +
  "\n";
conn.write(request);
while(!conn.eof) {
line = conn.readln(255);
if(line.substring(0, 1) == "\n") {
img_data = line.substring(1);
conn.close();
alert(img_data);
var img_file = new File(File(app.activeScript).parent + '/test.txt');
img_file.open('w');
img_file.write(img_data);
img_file.close();
alert("Done");

Answer 1

http://rorohiko.blogspot.com/2008_07_01_archive.html
demonstrates how to do the basics of what you need.
Cheers,
Kris