Help in downloading random image to digital photo frame

Hi, This is the first time I am posting to this forum despite having used gallery
(1 and now 2) for the past few years.

I have made a digital photo frame using an old laptop and am trying to download
random images (using a script) from my gallery and display them using feh.
In part I used my httpd logs to see what GLOSS did in order to understand what needs to be done.

I have only been partly successful at this and need some help or pointers in
my last step. What I am trying to do is in the following order –
1. Login to gallery using (this works)
lynx -dump "http://192.168.1.254/gallery2/main.php?g2_controller=remote:GalleryRemote&g2_form[protocol_version]=2.11&g2_form[cmd]=login&g2_form[uname]=loginName&g2_form[password]=plaintextpassword"

2. Then I try to get a random images itemId using the following which
outputs the url to a random image. (this step works)
lynx -dump "http://192.168.1.254//gallery2/main.php?g2_view=imageblock.External&g2_blocks=randomImage"

3. Once I parse the output of (2) I try to download the full image
(say 123456) using
Wget "http:/192.168.1.254/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=123456&g2_serialNumber=2"

This step fails and I see the following in the output
<div class="gbBlock gcBackground1">
<h2> Security Violation </h2>
</div>
<div class="gbBlock">
<p class="giDescription">
The action you attempted is not permitted.
</p>

<p class="giDescription">
<a href="main.php">Back to the Gallery</a>
</p>

Could someone point out what I am doing wrong? Does it have
anything to do with cookies or any other authentication that
is needed? Any help would be appreciated.

Rajarajan