function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}

var siteURL = "http://www.vtbeta.org/";
var banner1 = 'images/news_banners/honestScoundrels.png';
var banner2 = 'images/news_banners/gradesSpr2010.png';
var banner3 = 'images/news_banners/congratsNuClass.png';
var banner4 = 'images/news_banners/hokieIdol2010.png';
var imgs = new Array(banner1, banner2, banner3, banner4);
var button1 = 'images/preview_button.jpg';
var button2 = 'images/preview_button_select.jpg';
var buttons = new Array(button1, button2);
var delay = 8000;
var counter = 0;

function preloadImgs(){
  for(var i=0;i<imgs.length;i++) {
    MM_preloadImages(imgs[i]);
  }
}

function randomImages(){
  if(counter == (imgs.length)) {
    counter = 0;
  }

  if (counter == 0) {
	reset();
	MM_swapImage('previewButton1', '', buttons[1]);
  }
  else if (counter == 1) {
	reset();
	MM_swapImage('previewButton2', '', buttons[1]);
  }
  else if (counter == 2) {
	reset();
	MM_swapImage('previewButton3', '', buttons[1]);
  }
  else {
	reset();
	MM_swapImage('previewButton4', '', buttons[1]);
  }
  MM_swapImage('newsBanner', '', imgs[counter++]);
  setTimeout('randomImages()', delay);
}

/********************************************************
  CSS Change Banner
  use this function to change the image
********************************************************/
function changeBanner(id) {
	if (id == "preview1")
		document.getElementById("newsBanner").src = banner1;
	else if (id == "preview2")
		document.getElementById("newsBanner").src = banner2;
	else if (id == "preview3")
		document.getElementById("newsBanner").src = banner3;
	else
		document.getElementById("newsBanner").src = banner4;
}

/********************************************************
  Image Rollover
  use this function to change the image when you rollover it with a mouse
********************************************************/
function mouseOver(id) {
	if (id == "previewButton1")
		document.getElementById(id).src ="images/preview_button_select.jpg";
	else if (id == "previewButton2")
		document.getElementById(id).src ="images/preview_button_select.jpg";
	else if (id == "previewButton3")
		document.getElementById(id).src ="images/preview_button_select.jpg";
	else if (id == "previewButton4")
		document.getElementById(id).src ="images/preview_button_select.jpg";
}

function mouseOut(id) {
	if (id == "previewButton1")
		document.getElementById(id).src ="images/preview_button.jpg";
	else if (id == "previewButton2")
		document.getElementById(id).src ="images/preview_button.jpg";
	else if (id == "previewButton3")
		document.getElementById(id).src ="images/preview_button.jpg";
	else if (id == "previewButton4")
		document.getElementById(id).src ="images/preview_button.jpg";
	selectPreview();
}

/********************************************************
Select Preview
  use this function to change the selected preview image
********************************************************/
function selectPreview() {
	var link = document.getElementById("newsBanner").src;
	if (link == siteURL+banner1)
	{
		reset();
		document.getElementById("previewButton1").src = "images/preview_button_select.jpg";
	}
	else if (link == siteURL+banner2)
	{
		reset();
		document.getElementById("previewButton2").src = "images/preview_button_select.jpg";
	}
	else if (link == siteURL+banner3)
	{
		reset();
		document.getElementById("previewButton3").src = "images/preview_button_select.jpg";
	}
	else if (link == siteURL+banner4)
	{
		reset();
		document.getElementById("previewButton4").src = "images/preview_button_select.jpg";
	}
}

/********************************************************
Reset
  use this function to reset all buttons to not selected
********************************************************/
function reset() {
	document.getElementById("previewButton1").src = "images/preview_button.jpg";
	document.getElementById("previewButton2").src = "images/preview_button.jpg";
	document.getElementById("previewButton3").src = "images/preview_button.jpg";
	document.getElementById("previewButton4").src = "images/preview_button.jpg";
}