I am attempting to make a scroller that scrolls a long image along an x-axis and a few other elements. The problem I am having is that I want to add momentum to the image that scrolls and I am not sure how to go about doing this... can someone point me in the right direction? Here is my actionscript so far:

Code:
main.navigation.dragbar.onPress = function(){
	
	this.startDrag(false, -80, 0, 285, 0);
	
	moveBG();
	
	
}

main.navigation.dragbar.onRelease = function(){
	
	this.stopDrag();
	
}

function moveBG(){
	
	
	main.bg.onEnterFrame = function(){
		
		navigationX = main.navigation.dragbar._x * 4.25;
		
		if(main.navigation.dragbar._x < 1){}else{
		
		main.bg._x = (-main.navigation.dragbar._x) * 4.25};
		
		}
	
	}
}