Have just lifted this bit of code from pprune forum index page. If I read this correctly (and I am more than happy to be proved wrong), it looks like a bit of code which displays a slightly different screen if the valueadd cookie is detected. Clearly whoever wrote has the expectation that a cookie may be there.
<SCRIPT LANGUAGE=JavaScript><!--
// ValueParameters
ValueHost = "hs0182282";
ValueLoaded = false;
ValueID = "valueid";
ValueVersion = "1.1";
ValueWidth = 120;
ValueHeight = 60;
//--></SCRIPT> <SCRIPT LANGUAGE=Javascript src="http://oz.valueclick.com/jsmaster"></SCRIPT>
<SCRIPT LANGUAGE=JavaScript><!--
if (ValueLoaded) ValueShowAd();
//--></SCRIPT> <NOSCRIPT> <A HREF="http://oz.valueclick.com/redirect?host=hs0182282&size=120x60&b=forums2&v=0" TARGET="_top"><IMG SRC="http://oz.valueclick.com/cycle?host=hs0182282&size=120x60&b=forums2&noscr ipt=1" ALT="Click here to visit our sponsor" WIDTH=120 HEIGHT=60 BORDER=0 ALIGN=bottom></A>
</NOSCRIPT> <!-- vc active --></P>
</TD>
</TR>