Making Cookies

 #!/usr/local/bin/perl
 
 # file: preferences.pl
 
 use CGI qw(:standard :html3);
 
 # Some constants to use in our form.
 @colors=qw/aqua black blue fuschia gray green lime maroon navy olive
     purple red silver teal white yellow/;
 @sizes=("",1..7);
 
 # recover the "preferences" cookie.
 %preferences = cookie('preferences');
 
 # If the user wants to change the background color or her
 # name, they will appear among our CGI parameters.
 foreach ('text','background','name','size') {
     $preferences{$_} = param($_) || $preferences{$_};
 }
 
 # Set some defaults
 $preferences{'background'} = $preferences{'background'} || 'silver';
 $preferences{'text'} = $preferences{'text'} || 'black';
 
 # Refresh the cookie so that it doesn't expire.
 $the_cookie = cookie(-name=>'preferences',
                      -value=>\%preferences,
                      -path=>'/',
                      -expires=>'+30d');
 print header(-cookie=>$the_cookie);
 
 # Adjust the title to incorporate the user's name, if provided.
 $title = $preferences{'name'} ? 
     "Welcome back, $preferences{name}!" : "Customizable Page";
 
 # Create the HTML page.  We use several of the HTML 3.2
 # extended tags to control the background color and the
 # font size.  It's safe to use these features because
 # cookies don't work anywhere else anyway.
 print start_html(-title=>$title,
                  -bgcolor=>$preferences{'background'},
                  -text=>$preferences{'text'}
 		 );
 
 print basefont({-size=>$preferences{size}}) if $preferences{'size'} > 0;
 
 print h1($title);
 
 # Create the form
 print hr,
     start_form,
     
     "Your first name: ",
     textfield(-name=>'name',
               -default=>$preferences{'name'},
               -size=>30),br,
     
     table(
 	  TR(
 	     td("Preferred"),
 	     td("Page color:"),
 	     td(popup_menu(-name=>'background',
 			   -values=>\@colors,
 			   -default=>$preferences{'background'})
 		),
 	     ),
 	  TR(
 	     td(''),
 	     td("Text color:"),
 	     td(popup_menu(-name=>'text',
 			   -values=>\@colors,
 			   -default=>$preferences{'text'})
 		)
 	     ),
 	  TR(
 	     td(''),
 	     td("Font size:"),
 	     td(popup_menu(-name=>'size',
 			   -values=>\@sizes,
 			   -default=>$preferences{'size'})
 		)
 	     )
 	  ),
 
     submit(-label=>'Set preferences'),
     end_form,
     hr,
     end_html;