The problem here might become a little bit clearer if you split your method into three functions:
Now, every time you enter the action performed method, a new HashTable is created and assigned to the myObjects local variable. If the find button is pressed, it calls the find button's method. What you want to do is make the myObjects a member variable. It will then be accessible from every method. Just remember that you only need to initialize it once (not on every button click), or else you will have the same problem.
Piscis Babelis est parvus, flavus, et hiridicus, et est probabiliter insolitissima raritas in toto mundo.