var gwpCookieOverlay = {

    init: function() {
	
		var gwpDiv = document.createElement('div');
		gwpDiv.id = 'gwpcookiemessage';

		gwpDiv.innerHTML = '<h2>Notice to Visitors</h2><p>The law relating to website cookies changes on 26th May and requires that cookies only be used with your consent. BBC Top of the Pops is currently working on the best way to obtain your consent without spoiling your enjoyment of the website and we will notify you of these changes in due course.  <a href="http://www.bbcworldwide.com/cookies_update.aspx" rel="external">You can find out more about this here</a>.<a href="#" id="gwpclosedialog" onclick="gwpCookieOverlay.hideLayer(\'gwpcookiemessage\');return false;" >Close</a></p>';

		var cssStr = "#gwpcookiemessage{position:fixed; display:none; z-index:101; width:450px; top:30%; left:50%; background-color:#ffffff; border:solid 2px #7E7A84; padding: 10px; font-size:12px; color:#000; font-family:verdana,arial,helvetica;line-height: 17px; text-align: left; margin-left: -225px;} #gwpcookiemessage h2 { font-size: 14px; font-weight: bold; margin-bottom: 5px; } #gwpclosedialog { text-decoration: none; color: #000; font-weight: bold; display: block; margin-top: 5px;}";

		var gwpHead = document.getElementsByTagName('head')[0] ;
		var el = document.createElement('style');
		el.type = 'text/css';
		el.media = 'screen';
		if (el.styleSheet) el.styleSheet.cssText = cssStr; // IE method
		else el.appendChild(document.createTextNode(cssStr)); // others		
		gwpHead.appendChild(el);

		var gwpBody = document.getElementsByTagName("body")[0];
        gwpBody.appendChild(gwpDiv);

		var hasDisplayed = gwpCookieOverlay.readCookie('gwpCookieDisplayed');
		
		if(!hasDisplayed) {
			gwpCookieOverlay.showLayer('gwpcookiemessage');
			setTimeout("gwpCookieOverlay.hideLayer('gwpcookiemessage')", 25000);
			gwpCookieOverlay.createCookie('gwpCookieDisplayed','true',99);
		}
    },

    showLayer: function(layerName) {
		if (document.all) {
			document.all[layerName].style.display = "block";
		} else {
			document.getElementById(layerName).style.display = "block";
		}
	},		
	
    hideLayer: function(layerName) {
		if (document.all) {
			document.all[layerName].style.display = "none";
		} else {
			document.getElementById(layerName).style.display = "none";
		}
    },
	
	createCookie: function(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 = "";
		document.cookie = name+"="+value+expires+"; path=/";
	},

	readCookie :function(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;
	},

	eraseCookie: function(name) {
		gwpCookieOverlay.createCookie(name,"",-1);
	}	

};