... "CROATIA", "CYPRUS", "CZECH REPUBLIC", "DENMARK", Chapter 7: Graphical Examples with Perl/Tk- P2 The do_search( ) function will take an optional $url argument, ... beginning of a Perl/Tk script. We recognize that we want to utilize some of the HTML modules, and of course, the Tk module. We set up some basic globals in our program. The $query_interval is in minutes...