How to realize realtime update for shared work book

[chrisrita]

Dear everyone:

I am working out a workbook in which people can chat using the workbook sharing function. As you know new input made by certain user could be seen by others after saving by all of them. Ok, Let's make it easy. suppose there are only two users of a shared workbook, namely A and B. A input something and then saved the workbook. B on the other side had to save the workbook as well before he could see the information. now comes the problem. How can B know when to save the workbook to get the information from A? Two solutions: one is to have the workbook saved on a realtime basis, but the defect is obvious. It will be really slow. The other one is that maybe a msgbox could jump out to ask B to save the workbook. Having hit yes, B had the workbook saved automatically.

I prefer the second one, is it possible?
You may have better solutions, let me know it.

Thanks

Chris