diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -34,10 +34,12 @@
     #process parameters
     #problems
     @problems = []
-    params[:problem_id].each do |id|
-      next unless id.strip != ""
-      pid = Problem.find_by_id(id.to_i)
-      @problems << pid if pid
+    if params[:problem_id]
+      params[:problem_id].each do |id|
+        next unless id.strip != ""
+        pid = Problem.find_by_id(id.to_i)
+        @problems << pid if pid
+      end
     end
 
     #users
@@ -48,11 +50,11 @@
              end
 
     #set up range from param
-    since_id = params.fetch(:from_id, 0).to_i
-    until_id = params.fetch(:to_id, 0).to_i
+    @since_id = params.fetch(:from_id, 0).to_i
+    @until_id = params.fetch(:to_id, 0).to_i
 
     #calculate the routine
-    @scorearray = calculate_max_score(@problems, @users,since_id,until_id)
+    @scorearray = calculate_max_score(@problems, @users, @since_id, @until_id)
 
     #rencer accordingly
     if params[:button] == 'download' then
diff --git a/app/views/report/max_score.html.haml b/app/views/report/max_score.html.haml
--- a/app/views/report/max_score.html.haml
+++ b/app/views/report/max_score.html.haml
@@ -22,10 +22,10 @@
           Input minimum and maximum range of submission ID that should be included. A blank value for min and max means -1 and infinity, respectively.
         .form-group
           = label_tag :from, "Min"
-          = text_field_tag 'from_id', nil, class: "form-control"
+          = text_field_tag 'from_id', @since_id, class: "form-control"
         .form-group
           = label_tag :from, "Max"
-          = text_field_tag 'to_id', nil, class: "form-control"
+          = text_field_tag 'to_id', @until_id, class: "form-control"
   .col-md-4
     .panel.panel-primary
       .panel-heading
diff --git a/app/views/submissions/rejudge.js.haml b/app/views/submissions/rejudge.js.haml
--- a/app/views/submissions/rejudge.js.haml
+++ b/app/views/submissions/rejudge.js.haml
@@ -1,2 +1,2 @@
 :plain
-  $("body").prepend("<div class=\"alert alert-info\"> Submission #{@submission.id}'s task status has been chaned to \"#{@task.status_str}\" </div>")
+  $("body").prepend("<div class=\"alert alert-info\"> Submission #{@submission.id}'s task status has been changed to \"#{@task.status_str}\". It will be re-judged soon. </div>")