//JavaScript Banner Ad Rotator version 2.1 - last modified 16 November 2000
//Obtained from http://www.brettb.com/js_banner_ad_rotator.asp

//User defined variables - change these variables to alter the behaviour of the script
var ImageFolder = "BannerImages"; //Folder name containing the images
var ImageFileNames = new Array(
	'banner_image2.jpg',
	'banner_image3.jpg',
	'banner_image4.jpg'); //List of images to use
var ImageURLs = new Array(); //List of hyperlinks associated with the list of images
var DefaultURL = 'http://www.amazon.com/exec/obidos/redirect?tag=brettbcom&path=subst/home/home.html'; //Default hyperlink for the Banner Ad
var DisplayInterval = 20; //Number of seconds to wait before the next image is displayed
var TargetFrame = ""; //Name of the frame to open the hyperlink into

//Internal variables (do not change these unless you know what you are doing)
var IsValidBrowser = false;
var BannerAdCode = 0;
var BannerAdImages = new Array(NumberOfImages);
var DisplayInterval = DisplayInterval * 1000;
var NumberOfImages = ImageFileNames.length;

//Add a trailing forward slash to the ImageFolder variable if it does not already have one
if (ImageFolder.substr(ImageFolder.length - 1, ImageFolder.length) != "/" && ImageFolder != "") { ImageFolder += "/";
}

if (TargetFrame == '') {
var FramesObject = null;
} else {
var FramesObject = eval('parent.' + TargetFrame);
}


//Function runs when this page has been loaded and does the following:
//1. Determine the browser name and version  (since the script will only work on Netscape 3+ and Internet Explorer 4+).
//2. Start the timer object that will periodically change the image displayed by the Banner Ad.
//3. Preload the images used by the Banner Ad rotator script
function InitialiseBannerAdRotator() 
{
	//Determine the browser name and version
	//The script will only work on Netscape 3+ and Internet Explorer 4+
	var BrowserType = navigator.appName;
	var BrowserVersion = parseInt(navigator.appVersion);

	if (BrowserType == "Netscape" && (BrowserVersion >= 3)) {
		IsValidBrowser = true;
	}

	if (BrowserType == "Microsoft Internet Explorer" && (BrowserVersion >= 4)) {
		IsValidBrowser = true;
	}

	if (IsValidBrowser) {
		TimerObject = setTimeout("ChangeImage()", DisplayInterval);
		BannerAdCode = 0;
		for (i = 0; i < NumberOfImages; i++) {
			BannerAdImages[i] = new Image();
			BannerAdImages[i].src = ' ' + ImageFolder + ImageFileNames[i];
		}
	}
}

//Function to change the src of the Banner Ad image
function ChangeImage() 
{
	if (IsValidBrowser) {
		BannerAdCode = BannerAdCode + 1;
		if (BannerAdCode == NumberOfImages) {
			BannerAdCode = 0;
		}
		window.document.bannerad.src = BannerAdImages[BannerAdCode].src;
		TimerObject = setTimeout("ChangeImage()", DisplayInterval);
	}
}


//Function to redirect the browser window/frame to a new location,
//depending on which image is currently being displayed by the Banner Ad.
//If Banner Ad is being displayed on an old browser then the DefaultURL is displayed
function ChangePage() 
{
	if (IsValidBrowser) {
		if (TargetFrame != '' && (FramesObject)) {
			//FramesObject.location.href = ImageURLs[BannerAdCode];
		} else {
			//document.location = ImageURLs[BannerAdCode];
		}

	} else if (!IsValidBrowser) {
		//document.location = DefaultURL;
	}
}