var randomnumber;
		var x;
		var books;
		
		books = 3;
		
		randomnumber = Math.floor(Math.random() * books);
		randomnumber = randomnumber + 1;
		
		switch(randomnumber)
			{
			case 1:
				document.write('<iframe src="http://www.trifind.net/b/REV-3/SS-2010/TN.html" width=728 height=90 frameborder=0 scrolling=no marginwidth=0 marginheight=0></iframe>');
				break;
			case 2:
				document.write('<iframe src="http://www.trifind.net/b/REV-3/SS-2010/OH.html" width=728 height=90 frameborder=0 scrolling=no marginwidth=0 marginheight=0></iframe>');
				break;
			case 3:
				document.write('<iframe src="http://www.trifind.net/b/REV-3/SS-2010/TN.html" width=728 height=90 frameborder=0 scrolling=no marginwidth=0 marginheight=0></iframe>');
				break;
			}