Delegate question - send message back to controller from a view?

FROM : Jushin
DATE : Mon Dec 31 23:06:54 2007

In my program, I have two classes: Controller and NSCustomView.
Controller has a NSButton and a NSTextField, and when the button is
pressed, a function in the NSCustomView is triggered.
I used delegate to do this.

Now, my question is,
When a function call in the NSCustomView is finished, or even in the
process, I want to print out a message to the NSTextField in the
Controller.
How can I do this?

Thanks,