please help, splashscreen stops working when i switched to ajax

[Law]

I have a huge xml database that needs to be loaded into a website.

Please don't tell me to "do it server side" or anything - the college
it dept won't let me :-(.

it works fairly quick in college as its all internal.

http://www.waes.ac.uk/lc/datatest/amberley.html

anyway I have modified the quicker to load pages to use ajax as the
dodgy code before only ever worked with internet explorer:

http://www.waes.ac.uk/lc/resources/ajax/index.html

But now the loading screen doesnt work and users are sat there for 20
secs waiting for the list thinking something has gone wrong.

Is there any way to make the loading screen work with ajax?

I don't pretend to know much more than how to stitch code together so
it might be something really stupid.

Thanks for any help.