Add i18n for message in editor pop-up

app/assets/javascripts/ajax_form.js.erb

@@ -1,3 +1,4 @@
+<%#= encoding: utf-8 %>
 $(document).on('click', '#ajax_form_submit', function(){
 	// $('#ajaxForm').ajaxSubmit({
 	// 	beforeSubmit: function(a,f,o) {
@@ -35,6 +36,7 @@ $(document).on('click', '#ajax_form_submit', function(){
           })
           if(!sub){
           	$("#dyn_error").text("Cannot be empty.");
+          	$("#dyn_error").text("<%= I18n.t('cant_empty_star') %>");
             return false;
           }
        },