adSetNum = Math.round(3 * Math.random()) + 1;

function Ad(imgPath, url) {
	this.imgPath = imgPath;
	this.url = url;
}

// ads is a 2D array: ads[adSetNum][adNum]

ads = new Array('',
	// ad set 1:
	new Array('',
		new Ad("images/MSO_HDTVbanner90x100_20k.gif", "http://www.onlycablecan.com/samsung"),
		new Ad("images/ad_A2.gif", "javascript:cabletour()"),
		new Ad("images/ad_mc_500.gif", "mc_500.html")
	),
	// ad set 2:
	new Array('',
		new Ad("images/ad_B2.gif", "javascript:internettour()"),
		new Ad("images/xGameBanAd90x1801.gif", "form.php"),
		new Ad("images/90x100.jpg", "http://www.mediacomenews.com/enews/optin/optin_web.html")
	),
	// ad set 3:
	new Array('',
		new Ad("images/ad_C1.gif", "products_digitalcable.html"),
		new Ad("images/ad_C2.gif", "products_premiumsvcs.html"),
		new Ad("images/90x100.jpg", "http://www.mediacomenews.com/enews/optin/optin_web.html")
	),
	// ad set 4:
	new Array('',
		new Ad("images/ad_D1.gif", "corporate_pressroom.php"),
		new Ad("images/ad_D2.gif", "http://www.onmediaadsales.com"),
		new Ad("images/banner_120x90.gif", "http://www.mediacomcable.com/thinkfast")
	)			
);

function buildAd(adNum) {
	(adNum == 2) ? (adHeight = 180) : (adHeight = 100);

	document.write('<a href="' + ads[adSetNum][adNum].url + '"><img src="' + ads[adSetNum][adNum].imgPath);
	document.write('" alt="" width="90" height="' + adHeight + '" vspace="7" border="0" /></a>');
}