diff --git a/src/domain/session/room/RoomViewModel.js b/src/domain/session/room/RoomViewModel.js
index 94c78286..dfda5767 100644
--- a/src/domain/session/room/RoomViewModel.js
+++ b/src/domain/session/room/RoomViewModel.js
@@ -197,18 +197,80 @@ export class RoomViewModel extends ViewModel {
         }
     }
     
+    async _getMessageInformations (message) {
+        let msgtype = "m.text";
+        if (message.startsWith("/")) {
+            let command=message.substring(1).split(" ");
+            switch (command[0]) {
+                case "me":
+                   message = message.substring(4).trim();
+                   msgtype = "m.emote";
+                   break;
+               case "join":
+                   if (command.length==2) {
+                       let roomname = message.substring(5).trim();
+                       try {
+                           await this._options.client.session.joinRoom(roomname);
+                       } catch (exc) {
+                           if (exc.statusCode??exc.status==400) {
+                               this._sendError=new Error("/join : '"+roomname+"' was not legal room ID or room alias");
+                           } else if ((exc.statusCode??exc.status==502) || (exc.message="Internal Server Error")) {
+                               this._sendError=new Error("/join : room not found");
+                           } else {
+                               this._sendError=new Error("join syntax: /join <room-id>");
+                           }
+                           this._timelineError = null;
+                           this.emitChange("error");
+                       }
+                   } else {
+                       this._sendError=new Error("join syntax: /join <room-id>");
+                       this._timelineError = null;
+                       this.emitChange("error");
+                   }
+                   msgtype=undefined;
+                   message=undefined;
+                   break;
+               case "shrug":
+                   message="¯\\_(ツ)_/¯ "+message.substring(7);
+                   break;
+               case "tableflip":
+                    message="(╯°□°）╯︵ ┻━┻ "+message.substring(11);
+                    break;
+                case "unflip":
+                    message="┬──┬ ノ( ゜-゜ノ) "+message.substring(8);
+                    break;
+                case "lenny":
+                    message="( ͡° ͜ʖ ͡°) "+message.substring(7);
+                    break;
+                default:
+                    if (command[0][0]=="/") {
+                        message = message.substring(1).trim();
+                        break;
+                    } else {
+                        this._sendError=new Error("no command name '"+command[0]+"'");
+                        this._timelineError = null;
+                        this.emitChange("error");
+                        msgtype=undefined;
+                        message=undefined;
+                   }
+           }
+       }
+       return [msgtype, message];
+   }
+    
     async _sendMessage(message, replyingTo) {
         if (!this._room.isArchived && message) {
+            let messinfo = await this._getMessageInformations(message);
             try {
-                let msgtype = "m.text";
-                if (message.startsWith("/me ")) {
-                    message = message.substr(4).trim();
-                    msgtype = "m.emote";
-                }
-                if (replyingTo) {
-                    await replyingTo.reply(msgtype, message);
-                } else {
-                    await this._room.sendEvent("m.room.message", {msgtype, body: message});
+               let msgtype = messinfo[0];
+               let message = messinfo[1];
+               console.log("messinfo :",messinfo);
+               if (msgtype && message) {
+                   if (replyingTo) {
+                           await replyingTo.reply(msgtype, message);
+                   } else {
+                           await this._room.sendEvent("m.room.message", {msgtype, body: message});
+                   }
                 }
             } catch (err) {
                 console.error(`room.sendMessage(): ${err.message}:\n${err.stack}`);
diff --git a/src/platform/web/ui/css/themes/element/theme.css b/src/platform/web/ui/css/themes/element/theme.css
index 632d5bc5..16dfea12 100644
--- a/src/platform/web/ui/css/themes/element/theme.css
+++ b/src/platform/web/ui/css/themes/element/theme.css
@@ -521,6 +521,18 @@ a {
 
 .RoomView_error {
     color: var(--error-color);
+    background : #efefef;
+    padding-right : 20px;
+    padding-left : 20px;
+    overflow : hidden;
+    height : 0px;
+    transition : 0.25s all ease-out;
+}
+
+.RoomView_error:not(:empty) {
+   height : auto;
+    padding-top : 20px;
+    padding-bottom : 20px;
 }
 
 .MessageComposer_replyPreview .Timeline_message {