Need to simulate a listener for a variable

I have a Javascript setInterval that checks to see if the window.location of a certain frame has changed. If so, I tell it to send the value of the window.location into Flash through a variable.

My problem lies in getting Flash to see this change without using an onEnterFrame event. I do not want Flash to loop continuously to check if the value of the variable has changed if I do not have to. Is there any way I can trigger a function that detects change in value of the variable? Is there a way I can add a listener or onChanged (which is only for textfields) to a variable?

If not in Flash, is there a way for Javascript in one frame to tell when a different frame loads a different location without using setInterval? Is there possibly a listener that could be developed to listen to another frame’s information? If anyone has any light on this situation, please help! Trying to figure this out is driving me nuts! :h: