replace in opening quotations

node49.html

@@ -85,7 +85,7 @@ carries numbers as messages.
 
 <P>
 Messages not containing data make up <I>time sequences</I>.  So that you can
-see messages with no data, in Pd they are given the (arbitrary) symbol ``bang". 
+see messages with no data, in Pd they are given the (arbitrary) symbol "bang". 
 
 <P>
 
@@ -125,8 +125,8 @@ using two explicit delay objects:
  SRC="img339.png"
  ALT="\fbox{ $\mathrm{delay}$\ }">:
 <A NAME="3843"></A>simple delay.  You can specify the delay time in a creation argument or via
-the right inlet.  A ``bang" in the left inlet sets the delay, which then outputs
-``bang" after the specified delay in milliseconds.  The delay is <I>simple</I>
+the right inlet.  A "bang" in the left inlet sets the delay, which then outputs
+"bang" after the specified delay in milliseconds.  The delay is <I>simple</I>
 in the sense that sending a bang to an already set delay resets it to a new
 output time, canceling the previously scheduled one.
 
@@ -188,7 +188,7 @@ otherwise.
  SRC="img343.png"
  ALT="\fbox{ $\mathrm{sel}$\ }">:
 <A NAME="3846"></A>prune for specific numbers.  Numeric messages coming in the left inlet produce
-a ``bang" on the output only if they match a test value exactly.  The test
+a "bang" on the output only if they match a test value exactly.  The test
 value is set either by creation argument or from the right inlet.
 
 <P>
@@ -199,7 +199,7 @@ control streams implicitly in its connection mechanism, as illustrated by part
 (d) of the figure.  Most objects with more than one inlet synchronize all other
 inlets to the leftmost one.  So the <TT>float</TT> object shown in the figure
 resynchronizes its right-hand-side inlet (which takes numbers) to its
-left-hand-side one.  Sending a ``bang" to the left inlet outputs the most
+left-hand-side one.  Sending a "bang" to the left inlet outputs the most
 recent number <TT>float</TT> has received beforehand.
 
 <P>