replace in opening quotations

node22.html

@@ -81,10 +81,10 @@ have equal amplitudes.
 <P>
 The amplitude control in this example is taken care of by a new object called
 <TT>output~</TT>.  This isn't a built-in object of Pd, but is itself a Pd patch
-which lives in a file, ``output.pd".  (You can see the internals of
+which lives in a file, "output.pd".  (You can see the internals of
 <TT>output~</TT> by opening the properties menu for the box and selecting
-``open".)  You get two controls, one for amplitude in dB (100 meaning ``unit
-gain"), and a ``mute" button.  Pd's audio processing is turned on automatically
+"open".)  You get two controls, one for amplitude in dB (100 meaning "unit
+gain"), and a "mute" button.  Pd's audio processing is turned on automatically
 when you set the output level--this might not be the best behavior in
 general, but it's appropriate for these example patches.  The mechanism for
 embedding one Pd patch as an object box inside another is discussed in Section