my $webpage = "http://myurl/cgi-bin/search2011.cgi";
my $url = "$webpage?subject=$c_subject; #From earlier declaration already posted
print qq(<A HREF="$url">Subject</A>\n)."<br><br>";

##</code><code>##

    $query->param('foo','an','array','of','values');
This sets the value for the named parameter 'foo' to an array of values. This is one way to change the value of a field AFTER the script has been invoked once before. (Another way is with the -override parameter accepted by all methods that generate form elements.)