Reset error on new input

src/app/join-room/join-room.component.html

 <form>
   <div fxLayout="row" fxLayoutAlign="center" fxLayoutGap="10px">
     <mat-form-field class="input-block">
-      <input matInput #roomId placeholder="Room-Id"/>
-
+      <input matInput #roomId placeholder="Room-Id" (keypress)="reset()"/>
     </mat-form-field>
     <button mat-fab color="primary" (click)="joinRoom(roomId.value)">
       <mat-icon>send</mat-icon>

src/app/join-room/join-room.component.ts

@@ -44,4 +44,9 @@ export class JoinRoomComponent implements OnInit {
       this.notificationService.show('No room-id entered.');
     }
   }
+
+  reset(): void {
+    this.isExisting = true;
+    this.noInput = false;
+  }
 }