diff --git a/calendar/images/link.png b/calendar/images/link.png
new file mode 100644
index 0000000..736dc0d
Binary files /dev/null and b/calendar/images/link.png differ
diff --git a/calendar/images/log-out.png b/calendar/images/log-out.png
new file mode 100644
index 0000000..d283dfc
Binary files /dev/null and b/calendar/images/log-out.png differ
diff --git a/calendar/images/user.png b/calendar/images/user.png
new file mode 100644
index 0000000..0299427
Binary files /dev/null and b/calendar/images/user.png differ
diff --git a/calendar/index.html b/calendar/index.html
index e51aa93..cf73da0 100644
--- a/calendar/index.html
+++ b/calendar/index.html
@@ -29,6 +29,18 @@
 		<div class="container">
 			<div class="row">
 				<div class="navigation col-md-3">
+					<h4>User</h4>
+					<p>
+						<img src="images/user.png" alt="user">
+						Current user: <span id="username">unknown!</span>
+					</p>
+					<p>
+						<a href="javascript:logout()">
+							<img src="images/log-out.png" alt="log out">
+							Log out
+						</a>
+					</p>
+					<h4>Calendar</h4>
 					<div class="list-group">
 						<a class="list-group-item" href="#" onclick="showCategory(0)">
 							<img src="images/view-calendar-list.png" alt=""> Show appointments
@@ -41,7 +53,7 @@
 						<input type="checkbox" id="showPastAppointments" onclick="getListItems()">
 						Show appointments from the past
 					</label>
-					<h3>Categories:</h3>
+					<h4>Categories:</h4>
 					<div class="list-group" id="categoryList"></div>
 					<form method="get" action="javascript:createNewCategory()" id="createCategory">
 						<div class="input-group">
diff --git a/calendar/js/calendar.js b/calendar/js/calendar.js
index 4f855a1..31e0274 100644
--- a/calendar/js/calendar.js
+++ b/calendar/js/calendar.js
@@ -1,8 +1,8 @@
-var username = "root";
+var username = "";
 var appointments;
 var categories;
 var filter = 0;
-var host = "://dhbw.t-battermann.de/calendar/rewrite.php";
+var host = "//dhbw.t-battermann.de/calendar/redirect.php";
 
 function getListItems() {
 	var request = new XMLHttpRequest();
@@ -594,6 +594,44 @@ function deleteCategoryFromEventOnReadyStatusChangeEventHandler( request, eventI
 		}
 	}
 }
+function getCookie(name) {
+	var cname = name + "=";
+	var cookies = document.cookie.split(';');
+	for(var i=0;i<cookies.length; i++) {
+		var cookie = cookies[i];
+		while(cookie.charAt(0) == ' ')
+			cookie = cookie.substring(1);
+		if(cookie.indexOf(cname) == 0)
+			return cookie.substring(cname.length, cookie.length);
+	}
+	return "";
+}
+function setCookie(name, value) {
+	var d = new Date();
+	d.setTime( d.getTime() + 31536000000 );
+	document.cookie = name + "=" + value + "; expires=" + d.toUTCString();
+}
+function logout() {
+	var d = new Date();
+	d.setTime( d.getTime() - 86400000 );
+	document.cookie = "username=; expires=" + d.toUTCString();
+	location.reload();
+}
+function login() {
+	r = /[a-zA-Z0-9_ äöüÄÖÜß-]{1,10}/;
+	if (!r.exec(username) && !r.exec(getCookie("username")) ) {
+		do{
+			username = prompt("Please enter your username", "root");
+		}while(! r.exec(username) );
+	}else{
+		if( !r.exec(username) ){
+			username = getCookie("username");
+		}
+	}
+	setCookie("username", username);
+	document.getElementById("username").innerHTML = username;
+}
 
+login();
 showCategory(0);
 getCategories();