small server on Client ( Help PLZ ASAP)

Hi,
I guess you could help me with an idea.
I have a test implemented using JSP,servlets on Tomcat and Mysql DB.
The test is, divided into modules, and a module is loaded
completely on the client using DIV's,Java script...when the test is accessed.
Now the student types in his answer and click next, to
get his next question which also sends his answer to server DB. so here
we dont need server connection to show his next question.

Well, now v need to make it work on wireless network which
may b inconsistent, so if the wireless network is gone v dont
want our test to hang or loose data. We want to store data
on the client if network not available and push to server once
network is up.

I want this to work on both Windows and Mac. I need a server
or something like that which loads along with the test initially
and can be used to store data on the client and also send data
to server. Constraint is that we dont go to each system and install
a server. A request to our test shud do it. I am going mad.

Can u help me with this ? I tried with the signed applets writing onto
the disk, but, if the user who logs onto the system doesnt have sufficient
rights the applet fails atleast on Mac.

I heard abt Web GUI , does it have anything to do with this......