better login and change pwd

templates/change_pwd.html

@@ -1,6 +1,11 @@
 {% extends "base.html" %}
 {% block content %}
 <h3 class="text-center mb-4"><img style="width: 3em; height: 3em" src="/static/login.svg"></h3>
+{% with messages = get_flashed_messages() %}
+  {% for message in messages %}
+    <div class="alert alert-danger" role="alert">{{ message }}</div>
+  {% endfor %}
+{% endwith %}
 <form method="post">
 
   <input class="form-control mb-3" name="password_old" type="password" placeholder="Old Password" required>

templates/login.html

@@ -13,8 +13,8 @@
   </div>
 </div>
 <form method="post">
-  <input class="form-control mb-3" name="name" placeholder="Name" required>
-  <input class="form-control mb-3" name="password" type="password" placeholder="Password" required>
+  <input class="form-control mb-3" name="name" placeholder="{{ name_placeholder }}" required>
+  <input class="form-control mb-3" name="password" type="password" placeholder="{{ password_placeholder }}" required>
     <input
     type="image"
     src="/static/save.svg"