diff --git a/app/models/problem.rb b/app/models/problem.rb
--- a/app/models/problem.rb
+++ b/app/models/problem.rb
@@ -43,6 +43,7 @@
     if not importer.import_from_file(import_params[:file], 
                                      import_params[:time_limit], 
                                      import_params[:memory_limit],
+                                     import_params[:checker_name],
                                      import_to_db)
       problem.errors.add_to_base('Import error.')
     end
@@ -90,6 +91,11 @@
       problem.errors.add_to_base('No testdata file.')
     end
 
+    checker_name = 'text'
+    if ['text','float'].include? params[:checker]
+      checker_name = params[:checker]
+    end
+
     file = params[:file]
 
     if !problem.errors.empty?
@@ -106,7 +112,8 @@
     return [{
               :time_limit => time_limit,
               :memory_limit => memory_limit,
-              :file => file
+              :file => file,
+              :checker_name => checker_name
             },
             problem]
   end
diff --git a/app/views/problems/import.html.haml b/app/views/problems/import.html.haml
--- a/app/views/problems/import.html.haml
+++ b/app/views/problems/import.html.haml
@@ -32,6 +32,19 @@
             %br/
             You may put task description in *.html for raw html
             and *.md or *.markdown for markdown.
+            %br/
+            You may also put a pdf file for the task description
+      %tr
+        %td Checker:
+        %td= select_tag 'checker', options_for_select([['Text checker','text'],['Float checker','float']], 'text')
+      %tr
+        %td
+        %td
+          %span{:class => 'help'}
+            "Text" checker checks if the text (including numbers) is the same, ignoring any whitespace
+            %br/
+            "Float" checker checks if all numbers is within EPSILON error using formula |a-b| < EPSILON * max(|a|,|b|)
+
       - if @allow_test_pair_import
         %tr
           %td
diff --git a/lib/grader_script.rb b/lib/grader_script.rb
--- a/lib/grader_script.rb
+++ b/lib/grader_script.rb
@@ -50,7 +50,7 @@
 
       Dir.chdir(cur_dir)
       
-      return output
+      return "import CMD: #{cmd}\n" + output
     end
     return ''
   end
diff --git a/lib/testdata_importer.rb b/lib/testdata_importer.rb
--- a/lib/testdata_importer.rb
+++ b/lib/testdata_importer.rb
@@ -11,6 +11,7 @@
   def import_from_file(tempfile, 
                        time_limit, 
                        memory_limit,
+                       checker_name='text',
                        import_to_db=false)
 
     dirname = extract(tempfile)
@@ -19,7 +20,8 @@
       @log_msg = GraderScript.call_import_problem(@problem.name,
                                                   dirname,
                                                   time_limit,
-                                                  memory_limit)
+                                                  memory_limit,
+                                                  checker_name)
     else
       # Import test data to test pairs.