var pages = new Array(); 
var curPage = null;
var nextPage = null;
var prevPage = null;

function setupPages(containerId, defaultPageId) 
{
	pages[containerId] = new Array(); 
	var maxHeight = 0; var maxWidth = 0; 
	
	var container = document.getElementById(containerId); 
	var pageList = container.childNodes;
	for (var i=0; i < pageList.length; i++ ) 
	{ 
		var page = pageList[i]; 
		if (page.nodeType != 1) continue; 
		if (page.offsetHeight > maxHeight) maxHeight = page.offsetHeight; 
		if (page.offsetWidth  > maxWidth ) maxWidth  = page.offsetWidth; 
		
		var pageIntID = parseInt(page.id.substr((page.id.length-1), 1));
		pages[containerId][pageIntID] = page; 
		page.style.display = 'none'; 
	}
	/////// settting the width/height here causes problems in IE ///////
	//container.style.height = maxHeight + 'px'; 
	//container.style.width  = maxWidth + 'px'; 
	showPage(defaultPageId);
}

function showPage(pageId)
{
	if(typeof(pageId) == 'string')
		pageId = parseInt(pageId);
		
	var divID = 'divPage' + pageId;
	for (var con in pages) 
	{
		if (pages[con][pageId] != null) 
		{ 
			var page = document.getElementById(divID);
			page.style.display = 'block'; 
			curPage = pageId;
			prevPage = pages[con][(pageId - 1)] != null ? (pageId - 1) : null;
			nextPage = pages[con][(pageId + 1)] != null ? (pageId + 1) : null;
		}
		for (var i in pages[con]) 
		{ 
			var page = pages[con][i]; 
			if (page == undefined) continue; 
			if (page.id == divID) continue; 
			page.style.display = 'none';
		}
	}
	
	//display next and previous buttons as needed
	var btnPrevPg = document.getElementById('btnPrevPg');
	btnPrevPg.style.display = prevPage != null ? 'block' : 'none';
	var btnNextPg = document.getElementById('btnNextPg');
	btnNextPg.style.display = nextPage != null ? 'block' : 'none';
	
	//change nav-menu's selected value
	var navMenu = document.getElementById('nav_menu');
	navMenu.selectedIndex = pageId + 1;
	
	return false;
}