diff --git a/model.py b/model.py
index e7b855b..a6c45f8 100644
--- a/model.py
+++ b/model.py
@@ -41,6 +41,9 @@ class Model(object):
             self.model["clients"] = {}
         if not "sessions" in self.model:
             self.model["sessions"] = {}
+        for session in self.model["sessions"]:
+            if not "name" in self.model["sessions"][session]:
+                self.model["sessions"][session]["name"] = "Defaultname"
 
     @ApiMethod
     async def test_api(self, clientid):
@@ -56,34 +59,50 @@ class Model(object):
         await self.send_state(clientid)
 
     @ApiMethod
-    async def create_session(self, clientid) -> str:
-        sessionname = generate_random_id()
-        newsession = {"id": sessionname, "owner": clientid, "clients": []}
-        self.model["sessions"][sessionname] = newsession
+    async def create_session(self, clientid, sessionname) -> str:
+        if not sessionname:
+            raise Exception("Cant be empty!")
+        sessionid = generate_random_id()
+        newsession = {"id": sessionid, "owner": clientid, "clients": [], "name": sessionname }
+        self.model["sessions"][sessionid] = newsession
+        await self.send_state(clientid)
+
+    @ApiMethod
+    async def change_sessionname(self, clientid, sessionid, sessionname) -> str:
+        if not sessionname:
+            raise Exception("Cant be empty!")
+        if self.model["sessions"][sessionid]["owner"] == clientid:
+            self.model["sessions"][sessionid]["name"] = sessionname
+        await self.send_state(clientid)
+
+    @ApiMethod
+    async def leave_session(self, clientid):
+        sessionid = self.model["clients"][clientid]["session"]
+        del self.model["clients"][clientid]["session"]
+        self.model["sessions"][sessionid]["clients"].remove(clientid)
         await self.send_state(clientid)
 
     @ApiMethod
     async def join_session(self, clientid, sessionid):
         if sessionid in self.model["sessions"]:
-            # remove old session
-            if "session" in self.model["clients"][clientid]:
-                oldsession = self.model["clients"][clientid]["session"]
-                self.model["sessions"][oldsession]["clients"].remove(clientid)
-
-            self.model["sessions"][sessionid]["clients"].append(clientid)
+            # session exists
             self.model["clients"][clientid]["session"] = sessionid
-            await self.send_state(clientid)
-        else:
-            raise Exception(f"Session {sessionid} does not exist")
+            if not clientid in self.model["sessions"][sessionid]["clients"]:
+                self.model["sessions"][sessionid]["clients"].append(clientid)
+        await self.send_state(clientid)
 
     async def send_state(self, clientid):
         # TODO: compute state, send to client
-        session = "No session"
+        data = {}
         if "session" in self.model["clients"][clientid]:
-            session = self.model["clients"][clientid]["session"]
-        allsessions = [ name for name in self.model["sessions"] ]
-        username = self.model["clients"][clientid]["username"] if "username" in self.model["clients"][clientid] else "Joe"
-        data = {"currentsession": session, "allsessions": allsessions, "username": username}
+            sessionid = self.model["clients"][clientid]["session"]
+            data["session"] = {"id": sessionid, "name": self.model["sessions"][sessionid]["name"] }
+        allsessions = { name: { "id": name, "name": self.model["sessions"][name]["name"] } for name in self.model["sessions"] }
+        for session in allsessions:
+            if self.model["sessions"][session]["owner"] == clientid:
+                allsessions[session]["owner"] = True
+        data["allsessions"] = allsessions
+        data["username"] = self.model["clients"][clientid]["username"] if "username" in self.model["clients"][clientid] else "Joe"
         for socket in self.sockets[clientid]:
             await socket.send_json(data)
 
@@ -103,8 +122,10 @@ class Model(object):
         return clientid in self.model["clients"]
 
     def create_client(self, name="Joe") -> str:
+        if not name:
+            raise Exception("Username cannot be empty!")
         clientname = generate_random_id()
-        newclient = {"id": clientname, "username": name}
+        newclient = {"id": clientname, "username": name, "sessions": []}
         self.model["clients"][clientname] = newclient
         return clientname
 
diff --git a/static/renderer.js b/static/renderer.js
index dd1ab31..bf5a868 100644
--- a/static/renderer.js
+++ b/static/renderer.js
@@ -6,12 +6,16 @@ ws.onmessage = function(event) {
     const msg = JSON.parse(event.data);
 
     console.log(msg);
-
-    if (msg.hasOwnProperty('currentsession')) {
-        document.getElementById('current_session').innerText = msg.currentsession;
+    
+    if (msg.hasOwnProperty('session')) {
+        document.getElementById('active-session').innerText = msg.session["name"];
+        document.getElementById('btn-leave-session').style.display = "inline-block";
+    } else {
+        document.getElementById('active-session').innerText = "None";
+        document.getElementById('btn-leave-session').style.display = "none";
     }
     if (msg.hasOwnProperty('username')) {
-        document.getElementById('greeting').innerText = "Hello, " + msg.username + "!";
+        document.getElementById('label-username').innerText = msg.username;
     }
 
     if (msg.hasOwnProperty('allsessions')) {
@@ -19,13 +23,81 @@ ws.onmessage = function(event) {
 
         while (all_sessions.children.length) all_sessions.lastChild.remove();
 
-        for (let session of msg.allsessions) {
-            const button = document.createElement('button');
-            button.innerText = session;
-            button.onclick = async (e) => await fetch('api/join_session', {
-                method: 'POST', body: JSON.stringify({sessionid: session})
-            });
-            all_sessions.appendChild(button);
-        }
+        //for (let session in msg.allsessions) {
+        Object.keys(msg.allsessions).forEach( session => {
+
+            var sessionid = msg.allsessions[session]["id"]
+            var sessionname = msg.allsessions[session]["name"]
+            const tehsession = document.createElement('div');
+
+            const labelname = document.createElement('span');
+            owned = ("owner" in msg.allsessions[session]);
+            labelname.innerText = sessionname;
+            
+            tehsession.appendChild(labelname);
+
+            if (owned) {
+                const inputname = document.createElement('input');
+                inputname.style.display = "none";
+                const btnedit = document.createElement('button');
+                btnedit.innerText = '🖉'
+                const btnconfirm = document.createElement('button');
+                btnconfirm.innerText = '✔'
+                btnconfirm.style.display = "none"
+                const btndiscard = document.createElement('button');
+                btndiscard.innerText = '✘'
+                btndiscard.style.display = "none"
+
+                btnedit.onclick = async function (e) {
+                    inputname.style.display = "inline-block";
+                    inputname.value = sessionname;
+                    btnedit.style.display = "none";
+                    btnconfirm.style.display = "inline-block";
+                    btndiscard.style.display = "inline-block";
+                    labelname.style.display = "none";
+                }
+                btndiscard.onclick = async function (e) {
+                    inputname.style.display = "none";
+                    btnedit.style.display = "inline-block";
+                    btnconfirm.style.display = "none";
+                    btndiscard.style.display = "none";
+                    labelname.style.display = "inline-block";
+                }
+                btnconfirm.onclick = async function (e) {
+                    text = inputname.value;
+                    if (Boolean(text)) {
+                        let data = {"sessionid": sessionid, "sessionname": text};
+                        await fetch('api/change_sessionname', {
+                            method: 'POST',
+                            body: JSON.stringify(data),
+                        });
+                        inputname.style.display = "none";
+                        btnedit.style.display = "inline-block";
+                        btnconfirm.style.display = "none";
+                        btndiscard.style.display = "none";
+                        labelname.style.display = "inline-block";
+                    } else {
+                        console.log("cant be empty");
+                    }
+                }
+
+                tehsession.appendChild(inputname);
+                tehsession.appendChild(btnedit);
+                tehsession.appendChild(btnconfirm);
+                tehsession.appendChild(btndiscard);
+            }
+
+            if ((! msg.hasOwnProperty('session')) || msg.session["id"] != sessionid) {
+                const btnjoin = document.createElement('button');
+                btnjoin.innerText = "Join";
+                btnjoin.onclick = async (e) => await fetch('api/join_session', {
+                    method: 'POST', body: JSON.stringify({"sessionid": sessionid})
+                });
+
+                tehsession.appendChild(btnjoin);
+            }
+            
+            all_sessions.appendChild(tehsession);
+        })
     }
 };
diff --git a/ui.html b/ui.html
index 279e14c..6f9e4db 100644
--- a/ui.html
+++ b/ui.html
@@ -4,49 +4,104 @@
 <head>
     <title>leafblade Minecraft Server</title>
     <meta charset="UTF-8"/>
+    <style>
+div {
+    border: 1px solid;
+    margin: 5px;
+}
+</style>
 </head>
 
 <body>
 <span id="greeting"></span><br>
+<div id="username-area">
+    <span id="greeting">Hello, </span>
+    <span id="label-username">_</span>
+    <input id="input-set-username" style="display: none;">
+    <button id="btn-edit-username">🖉</button>
+    <button id="btn-discard-username" style="display: none;">✘</button>
+    <button id="btn-confirm-username" style="display: none;">✔</button>
+</div>
 <br>
-<span id="current_session">You are not in any session.</span><br>
+
+<div>
+<span>Active Session:</span><span id="active-session">None</span>
+<button id="btn-leave-session">Leave Session</button>
+<br>
+</div>
+
+<br>
+
+<span>Available sessions</span><br>
 <div id="all_sessions"></div><br>
 <br>
-<button id="btn_create_session">Create session</button>
+<br>
+
+<span>Create Session</span><br>
+<input id="input-create-session">
+<button id="btn-create-session">+</button>
+<br>
+<!--<button id="btn_create_session">Create session</button>
 <br><br><br>
-<input id="set_username" type="text" placeholder="New username" />
-<button id="btn_set_username">Set Username</button>
-<br><br><br>
-<input id="join_session_id" type="text" placeholder="Enter session id" />
-<button id="btn_join_session">Join session</button>
+-->
 
 <script src="../static/renderer.js"></script>
 <script>
-    document.getElementById("btn_create_session").onclick = async function (e) {
-        let data = {};
+    // username management
+    document.getElementById("btn-edit-username").onclick = async function (e) {
+        document.getElementById("btn-confirm-username").style.display = "inline-block";
+        document.getElementById("btn-discard-username").style.display = "inline-block";
+        document.getElementById("btn-edit-username").style.display = "none";
+        document.getElementById("label-username").style.display = "none";
+        document.getElementById("input-set-username").style.display = "inline-block";
+        document.getElementById("input-set-username").value = document.getElementById("label-username").innerText;
+    }
+    document.getElementById("btn-discard-username").onclick = async function (e) {
+        document.getElementById("btn-confirm-username").style.display = "none";
+        document.getElementById("btn-discard-username").style.display = "none";
+        document.getElementById("btn-edit-username").style.display = "inline-block";
+        document.getElementById("label-username").style.display = "inline-block";
+        document.getElementById("input-set-username").style.display = "none";
+    }
+    document.getElementById("btn-confirm-username").onclick = async function (e) {
+        var text = document.getElementById("input-set-username").value;
+        if (Boolean(text)) {
+            let data = {"username": text};
 
-        await fetch('api/create_session', {
-            method: 'POST',
-            body: JSON.stringify(data),
-        })
-    };
-    document.getElementById("btn_join_session").onclick = async function (e) {
-        let text = document.getElementById("join_session_id").value;
-        let data = {"sessionid": text};
+            await fetch('api/change_username', {
+                method: 'POST',
+                body: JSON.stringify(data),
+            })
+            document.getElementById("btn-confirm-username").style.display = "none";
+            document.getElementById("btn-discard-username").style.display = "none";
+            document.getElementById("btn-edit-username").style.display = "inline-block";
+            document.getElementById("label-username").style.display = "inline-block";
+            document.getElementById("input-set-username").style.display = "none";
+        } else {
+            console.log("cant be empty");
+            document.getElementById("btn-confirm-username").style.display = "none";
+            document.getElementById("btn-discard-username").style.display = "none";
+            document.getElementById("btn-edit-username").style.display = "inline-block";
+            document.getElementById("label-username").style.display = "inline-block";
+            document.getElementById("input-set-username").style.display = "none";
+        }
+    }
+    
+    document.getElementById("btn-leave-session").onclick = async (e) => await fetch('api/leave_session', {
+                        method: 'POST', body: JSON.stringify({})
+                    });
 
-        await fetch('api/join_session', {
-            method: 'POST',
-            body: JSON.stringify(data),
-        })
-    };
-    document.getElementById("btn_set_username").onclick = async function (e) {
-        let text = document.getElementById("set_username").value;
-        let data = {"username": text};
 
-        await fetch('api/change_username', {
-            method: 'POST',
-            body: JSON.stringify(data),
-        })
+    document.getElementById("btn-create-session").onclick = async function (e) {
+        var text = document.getElementById("input-create-session").value;
+        if (Boolean(text)) {
+            let data = {"sessionname": text};
+
+            await fetch('api/create_session', {
+                method: 'POST',
+                body: JSON.stringify(data),
+            })
+        }
     };
 </script>
 </body>