Lock form while computing PoW

boards/static/js/form.js

@@ -72,6 +72,7 b' function addHiddenInput(form, name, valu'
 
             form.submit();
             form.find('input[type=submit]').toggle();
+            $("#form :input").prop('readonly', false);
         };
 
         var form = $('#form');
@@ -79,6 +80,7 b' function addHiddenInput(form, name, valu'
         submitButton.click(function() {
             showAsErrors(form, gettext('Computing PoW...'));
             submitButton.toggle();
+            $("#form :input").prop('readonly', true);
 
             var msg = $('textarea').val().trim();