or download this
if ($ENV{'HTTP_USER_AGENT'} =~ /W3C\_CSS\_Validator\_JFouffa/)
{
...
print " <meta http-equiv=\"content-type\" content=\"application\/xh
+tml+xml; charset=utf-8\" />\n";
print " <link rel=\"stylesheet\" type=\"text/css\" href=\"css3.css\
+" media=\"screen, projection, print\" />\n";
}