function pb_page_initialise() {
		pb_select_banner_header();
	}
	
	// should be able to just copy this function for another footer banner - pb_select_banner_footer(). 
	// just replace the string values - array elements, cookie names and image span id.
	function pb_select_banner_header() {
		if (document.getElementById('parentbook_header_span') != null) {
			// hide the image
			document.getElementById('parentbook_header_span').style.display = 'none';		
			
			// Just add the new array slides and you are done.
			var parentbook_banner = new Array();
			parentbook_banner[0] = '<a href="http://www.mums.earthlings.co.nz"><img src="http://www.earthlings.co.nz/images/parentBook/slideshow-big-banner-pb.gif" width="755" height="170" border="0"></a>';
			parentbook_banner[1] = '<a href="http://www.jakonappies.com/" target="_blank" rel="nofollow"><img src="http://www.earthlings.co.nz/images/parentBook/jakonappiesadbig.gif" width="755" height="170" border="0"></a>';
			parentbook_banner[2] = '<a href="http://www.ecomoon.co.nz/" target="_blank" rel="nofollow"><img src="http://www.earthlings.co.nz/images/parentBook/ecomoonbigad.gif" width="755" height="170" border="0"></a>';
	
	
	
			////NO need to edit beyond here. Array items will be counted, and new cookie created if item count is different.////
	
			// saved slide display order
			pb_banner_displayorder = readCookie('pbcookie_header_displayorder');
	
			if (pb_banner_displayorder == null) {
				pb_banner_displayorder = createBannerCookie(parentbook_banner,'pbcookie_header_displayorder');
			} else {
				// convert cookie string to array
				pb_banner_displayorder = pb_banner_displayorder.split(',');
				
				if (pb_banner_displayorder.length != parentbook_banner.length) {
					// Number of slides has changed. Create new cookie
					pb_banner_displayorder = createBannerCookie(parentbook_banner,'pbcookie_header_displayorder');
				}
			}
			
			// saved slide position
			pb_banner_slideorder = readCookie('pbcookie_header_slideorder');
			if (pb_banner_slideorder == null || parseInt(pb_banner_slideorder) >= parentbook_banner.length) {
				pb_banner_slideorder = 0;
			}
			createCookie('pbcookie_header_slideorder',parseInt(pb_banner_slideorder) + 1,365);
	
			// assign the slide
			pb_banner_slide = pb_banner_displayorder[pb_banner_slideorder];
			if (pb_banner_slide != null) {
				document.getElementById('parentbook_header_span').innerHTML = parentbook_banner[pb_banner_slide];
			}
	
			// display the image
			document.getElementById('parentbook_header_span').style.display = 'block';
		}
	}
	
	function createBannerCookie(banner,cookiename) {
		// count number of banner slides items
		var pb_banner_displayorder = new Array();
		for (i=0; i < banner.length; i++) { pb_banner_displayorder.push(i); }
		// randomise banner display order
		pb_banner_displayorder.sort(function() {return 0.5 - Math.random()});
		// save display order cookie. expires 1 year.
		createCookie(cookiename,pb_banner_displayorder,365);
		
		return pb_banner_displayorder;
	}
	
	function createCookie(name,value,days) {
		if (days) {
			var date = new Date();
			date.setTime(date.getTime()+(days*24*60*60*1000));
			var expires = "; expires="+date.toGMTString();
		}
		else var expires = "";

		// test
//		document.cookie = name+"="+value+expires+"; path=/";

// live
		document.cookie = name+"="+value+expires+"; path=/; domain=earthlings.co.nz";
	}
	
	function readCookie(name) {
		var nameEQ = name + "=";
		var ca = document.cookie.split(';');
		for(var i=0;i < ca.length;i++) {
			var c = ca[i];
			while (c.charAt(0)==' ') c = c.substring(1,c.length);
			if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
		}
		return null;
	}