our %myhash;

my $cgi = CGI->new();

my %funchash = ( 'SUBA'    => \&suba,

                 'SUBB'    => \&subb );


my $pjx = CGI::Ajax->new( %funchash );


my $var1="aaa";

$myhash{typea}=$var1;


my $template="html/mypage.html";

my $tmpl= HTML::Template::Pro->new(filename => $template,loop_context_vars=>1,debug=>1,global_vars=>1);


print $pjx->build_html( $cgi, $tmpl->output)


sub suba {

# this is invoked by user clicking on dropdown box A

$myhash{typeb}="bbbb";

print "$myhash{typea}";  <- this is shown correctly 

print "$myhash{typeb}";  <-  this is shown correctly 

} 


sub subb { 

# this is invoked after user clicked dropdown box B after A 

$myhash{typec}="cccc"; 

print "$myhash{typea}";  <- this is shown correctly 

print "$myhash{typeb}";  <-  this is _NOT_ shown 
 print "$myhash{typec}";  <-  this is shown correctly 



}