This is an intranet SQL query generation application.
I use server-side scripts to read and place server data on several list boxes (mainly server-side scripts up to this point), then users make selections from these list boxes, during this user interface time, I stay on the client side to process the interaction between my page and user entries, since this is all between end-user and whatever is dsiplayed on screen (this part is client-side).
After they hit 'submit' button, I use data users entered to create SQL query and to retrieve recordsets, and display both the SQL query created and the recordsets on the next page, possibly displaying the data on a spreadsheet.
At this point, I need to be able to access the SQL query string created or the recordsets returned to place the data on the screen. Since the data is large and other function is needed, I may choose to use the spreadsheet for the display.
Can I use server-side scripts for all this? Maybe, but I'm not sure yet. It just makes sense for me to process this on the client side using <script> </script>, instead of ASP's <% %>.
The only reason I can think of that I really transfer data between server side and client side is if I had to generate data based off a drop down box and I didn't want to do a return trip for each new selection. A situation like I have 3 drop down boxes, the selection in drop down 1 will determine whats in 2, selection in 2 determines 3, etc. Something like that I really don't want to do a round trip for each of the selections of the drop down. I would do a server side script that would create a client side script that drives the adding and removing of data from the drop downs. I'm sure there are other situations but I havn't come across any other ones where I would have to pass data between client and server side scripts.