$tmpl_form->param(
    ACTION   => "/path/to/my/script.cgi",
    DEFAULT  => $request->param("searchkey"),
    PARCEL   => $request->param("searchby") eq "Parcel"  ? "true" : "",
    NAME     => $request->param("searchby") eq "Name"    ? "true" : "",
    ADDRESS  => $request->param("searchby") eq "Address" ? "true" : "",
);