s group (), it spits 
         out an extra field, known as a marked sub-expression, for example the 
         expression:</P>
      <PRE>(\w+)\W+(\w+)</PRE>
      <P>
         Has two marked sub-expressions (known as $1 and $2 respectively), in addition 
         the complete match is known as $&amp;, everything before the first match as $`, 
         and everything after the match as $'.&nbsp; So if the above expression is 
         searched for within "@abc def--", then we obtain:</P>
      <BLOCKQUOTE d