scrollChecker = setInterval("scrollNav()", 500);
myEffect = "undefined"
function sub_nav(section) {
			new Effect.ScrollTo(section);
			myEffect = new Effect.Move('leftNav', { x: 0, y:$(section).offsetTop-150, mode: 'absolute', afterFinish:clearName});
		}
function scrollNav(){
	if(myEffect == "undefined"){
		mypageYOffset = getYOffset()
		var scrollToPos = mypageYOffset-150
		if(scrollToPos>$('endofpage').offsetTop-$('leftNav').getHeight()-150){
			scrollToPos = $('endofpage').offsetTop-$('leftNav').getHeight()-150
		}
		if(scrollToPos<0){
		scrollToPos = 0
		}
		myEffect = new Effect.Move('leftNav', { x: 0, y:scrollToPos, mode: 'absolute' , afterFinish:clearName, duration:.5});
	}
	
}
function getYOffset() {
    var pageY;
    if(typeof(window.pageYOffset)=='number') {
       pageY=window.pageYOffset;
    }
    else {
       pageY=document.documentElement.scrollTop;
    }
    return pageY;
}
function clearName(){
	myEffect = "undefined";
}