Alert the user that this website is using cookies.

cookiePolicy.js

(function(messageContent) {
	var cookieName = 'cookiePolicyHide';
	function hideMessage() {
		message.parentNode.removeChild(message);
		document.cookie = cookieName + '=1;path=/';
	}
	function messageHidden() {
		var cookies = document.cookie.split(';');
		for(var index = 0; index < cookies.length; index++) {
			while(cookies[index].charAt(0) === ' ') {
				cookies[index] = cookies[index].substring(1);
			}
			if(cookies[index].indexOf(cookieName + '=') === 0) {
				return cookies[index].substring((cookieName + '=').length, cookies[index].length);
			}
		}
		return null;
	}
	
	if(!messageHidden()) {
		var message = document.createElement('div');
		message.textContent = messageContent;
		message.style.background = '#dddddd';
		message.style.color = '#000000';
		message.style.fontSize = '12px';
		message.style.textAlign = 'center';
		message.style.padding = '2px 10px';
		message.style.position = 'absolute';
		message.style.top = 0;
		message.style.left = 0;
		message.style.right = 0;
		
		var close = document.createElement('div');
		close.textContent = '×';
		close.style.cursor = 'pointer';
		close.style.float = 'right';
		close.style.fontSize = '16px';
		close.style.color = '#888888';
		
		message.insertBefore(close, message.childNodes[0]);
		
		document.body.appendChild(message);
		
		close.addEventListener('click', function() {
			hideMessage();
		});
	}
})('Mit der Nutzung dieser Webseite erklären Sie sich damit einverstanden, dass wir Cookies einsetzen.');