function extractUrls(str) {
  startTag = "http://";
  endTag = ".jpg";

  urls = "";
  remaining = str;
  while (true) {
    start = pos(remaining, startTag);
    if (start == 0) {
      return urls;
    }
    remaining = mid(remaining, start);

    end = pos(remaining, endTag);
    if (end == 0) {
      return urls;
    }
    if (urls != "") {
      urls = urls + "\n";
    }
    urls = urls + left(remaining, end + len(endTag) - 1);
    remaining = mid(remaining, end);
  }
}

for (y = 1; y <= Bottom; y++) {
  for (x = 1; x <= Right; x++) {
    urls = extractUrls([x,y]);
    if (urls != "") {
      [x,y] = urls;
    }
  }
}