How can i use AmbientChanged in ocx

With this event the program tell me when a property value change.
But it works when i change the name of ocx control.

How can i know when my property that i make it change the value
With this action how can i do something like to notify a value of my program.

This event occurs when one of the Ambient properties change (type Ambient. and in the dropdown box you see all the properties).
For instance, drop a usercontrol on a form, and change the form's font property, the ambientchanged event will occur.

I'm not sure how to use this, I thought it applies to an ambient property of the direct parent (container) of the control, but when I put the testcontrol on a picturebox and I change the backcolour of a form, this event is also raised.