var curNafTab = 'new';
var curNum = 0;
var maxline = 5;
var titmer;
var count = 0;
function changeNafTab (tab) {
	if (tab != curNafTab) {
		
		if (tab == "fin") {
			document.getElementById('tab_link').style.backgroundImage = 'url(img/menu_bar2.gif)';
		} else {
			document.getElementById('tab_link').style.backgroundImage = 'url(img/menu_bar1.gif)';
		}
		
		document.getElementById(curNafTab + 'List').style.display = 'none';
		document.getElementById(tab + 'List').style.display = 'block';
		
		curNafTab = tab;
		curNum = 0;
		initNaf(tab);
	}
}
function initNaf (tab) {
	var maxNum = getListLength(tab);
	var limit = maxline;
	if (maxNum < limit) limit = maxNum;
	for (i=0; i<maxNum; i++) {
		if (i < limit) {
			nafDisplay(tab, i, 'block');
		}
		else {
			nafDisplay(tab, i, 'none');
		}
	}
	curNum = 0;
}
function setNaf (tab, topNum) {
	clearNaf (tab);
	curNum = topNum;
	timer = setInterval("nafDisplay2()", 60);
//	for (i=0; i<maxline; i++) {
//		nafDisplay(tab, (topNum + i), "block");
//	}
	
}





function clearNaf (tab) {
	for (i=0; i<maxline; i++) {
		nafDisplay(tab, (curNum + i), "none");
	}
}
function nafScrollDown() {
	var maxNum = getListLength(curNafTab);
	if (curNum + maxline == maxNum) {
		//setNaf (curNafTab, 0);
	}
	else {
		setNaf (curNafTab, curNum + maxline);
	}
}
function nafScrollUp() {
	var maxNum = getListLength(curNafTab);
	if (curNum == 0) {
		//setNaf (curNafTab, maxNum - maxline);
	}
	else {
		setNaf (curNafTab, curNum - maxline);
	}
}
function nafDisplay(tab, id, mode) {
	document.getElementById(tab + 'List').getElementsByTagName("li")[id].style.display = mode;
}
function nafDisplay2() {
	
	var id = curNum + count;
	document.getElementById(curNafTab + 'List').getElementsByTagName("li")[id].style.display = "block";
	
	count++;
	if (count == maxline) {
		clearInterval(timer);
		count = 0;
	}
}
function getListLength(tab) {
	return document.getElementById(tab + 'List').getElementsByTagName("li").length;
}