Fix more raise statments in the docs.
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index ce47164..5a182a9 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -329,7 +329,8 @@
            if ok in ('y', 'ye', 'yes'): return True
            if ok in ('n', 'no', 'nop', 'nope'): return False
            retries = retries - 1
-           if retries < 0: raise IOError, 'refusenik user'
+           if retries < 0:
+               raise IOError('refusenik user')
            print(complaint)
 
 This function can be called either like this: ``ask_ok('Do you really want to