Opening two edit pages at once - data corruption

I have a simple jsf page with a table of Employees, now when the user clicks on a button edit, I put the employee with the associated row on the session map and open the edit employee page which uses the Employee from the session map for manipulating the data. Now what can happen is that that the user would try to edit two Employees at once, with the "open page in new window" from his/hers browser meaning that both pages will refer to the same object hence when the user will press save then the other Employee record will get corrupted which is very bad.

How did you solve this issue?

[602 byte] By [HaKia] at [2007-11-27 0:23:02]