Can X position of mc trigger a function?

programming flash
1

I am wondering if there is a way to use the x position of mc to start some other actions…

I am have been using setInterval throughout the movie I am working on to time all of my actions, but was hoping that I could use some such as the code below to fade an mc when _x equals a certain number (this is a scrolling clip, which is now set to stop at a certain x value, I want it to stop, then fade)

function fadeOut (){
	if (_root.holder26._x <= -1825) {
fading code goes here

So far it does not seem to be working, although I am working on getting the alpha fade to work so that may be the problem.

I have done some searching for this topic on this forum and others and have not found much so I am wondering if this is even possible.