Add IDs back to the buttons, giving each one a unique id.

resources/views/signin.ejs

@@ -78,16 +78,16 @@
             </ul>
 
             <div class="submit cf forminputs start">
-                <button><%- gettext('Next') %></button>
+                <button id="next"><%- gettext('Next') %></button>
             </div>
 
             <div class="submit cf forminputs password_entry">
-                <button><%- gettext('Sign In') %></button>
+                <button id="signIn"><%- gettext('Sign In') %></button>
             </div>
 
             <div class="submit cf forminputs vpassword_entry">
                 <p class="cf">
-                  <button><%- gettext('Verify Email') %></button>
+                  <button id="verifyEmail"><%- gettext('Verify Email') %></button>
                 </p>
 
                 <p class="tospp cf">