Problem with "adding thumbnails" tutorial by Kirupa

[COLOR=#0000ff]Hi all,[/COLOR]

[COLOR=#0000ff]I’m just after completing the adding thumbnails tutorial bu Kirupa. I was able to work through the tutorial fine and got the sample photo gallery working fine but when I try to substitute my own pictures for the sample pictures I get the following error[/COLOR]

Error opening URL “file:///U|/example%5Fgallery/thumbnail%5Ffinal/undefined”

The only code I changed was in the xml file and was

<pic>
<image>U:\example_gallery\rocky_2.png</image>
<caption>Rocky 2</caption>
<thumbnail>U:\example_gallery\rocky_2_sm.png</thumbnail>
</pic>

[COLOR=blue]as opposed to the original[/COLOR]

[COLOR=#0000ff]<[/COLOR][COLOR=#990000]pic[/COLOR][COLOR=#0000ff]>[/COLOR]
[COLOR=#0000ff]<[/COLOR][COLOR=#990000]image[/COLOR][COLOR=#0000ff]>[/COLOR][COLOR=#0000ff]</[/COLOR][COLOR=#990000]image[/COLOR][COLOR=#0000ff]>[/COLOR]

[COLOR=#0000ff]<[/COLOR][COLOR=#990000]caption[/COLOR][COLOR=#0000ff]>[/COLOR]Kresge[COLOR=#0000ff]</[/COLOR][COLOR=#990000]caption[/COLOR][COLOR=#0000ff]>[/COLOR]

[COLOR=#0000ff]<[/COLOR][COLOR=#990000]thumbnail[/COLOR][COLOR=#0000ff]>[/COLOR][COLOR=#0000ff]</[/COLOR][COLOR=#990000]thumbnail[/COLOR][COLOR=#0000ff]>[/COLOR]

[COLOR=#0000ff]<[/COLOR][COLOR=#990000]link[/COLOR][COLOR=#0000ff]>[/COLOR]http://web.mit.edu/evolving/projects/kresge/[COLOR=#0000ff]</[/COLOR][COLOR=#990000]link[/COLOR][COLOR=#0000ff]>[/COLOR]

[COLOR=#0000ff]</[/COLOR][COLOR=#990000]pic[/COLOR][COLOR=#0000ff]>[/COLOR]

[COLOR=#0000ff]Although I do have some prior experience with some other programming languages this is the first time I’ve used xml or flash and I am unsure as to what mistake i’ve made.[/COLOR]
[COLOR=#0000ff]Any help or advice would be greatly appreciated[/COLOR]

[COLOR=#0000ff]Thanks in advance,[/COLOR]
[COLOR=#0000ff]Derm[/COLOR]