How do I change an attribute for something from another class?

Is there any way to reach a method (in this case a method changing the attribute of a swing object, let's say a JTextBox) from another class without making another instance of the object (logically, I don't want to make a new window for every textbox that is to be modified).

Any alternative solutions would be welcome too, I just don't know how to go about it.

[377 byte] By [hogla] at [2007-11-27 7:56:22]