diff --git a/lib/tempfile.rb b/Users/hongli/Projects/better/tempfile.rb
index 752fd48..7a48603 100755
--- a/lib/tempfile.rb
+++ b/Users/hongli/Projects/better/tempfile.rb
@@ -82,6 +82,9 @@ class Tempfile < DelegateClass(File)
   MAX_TRY = 10  # :nodoc:
   @@cleanlist = []
   @@lock = Mutex.new
+  
+  class CreationError < StandardError # :nodoc:
+  end
 
   # call-seq:
   #    new(basename, [tmpdir = Dir.tmpdir], [options])
@@ -155,7 +158,7 @@ class Tempfile < DelegateClass(File)
       rescue
         failure += 1
         retry if failure < MAX_TRY
-        raise "cannot generate tempfile `#{tmpname}'"
+        raise CreationError, "cannot generate tempfile `#{tmpname}'"
       end
     }
 
@@ -304,6 +307,7 @@ class Tempfile < DelegateClass(File)
     def callback(data)	# :nodoc:
       pid = $$
       Proc.new {
+
 	if pid == $$
 	  path, tmpfile, cleanlist = *data