# Untested. use CGI; $q = new CGI(); # Input. my $num1 = $q->param('num1'); my $num2 = $q->param('num2'); $num1 = undef if ($q->param{'clear_num1'}); $num2 = undef if ($q->param{'clear_num2'}); # Validate. $num1 = undef unless (defined($num1) && $num1 =~ /^\d+$/); $num2 = undef unless (defined($num2) && $num2 =~ /^\d+$/); # Start HTML. print($q->header()); print($q->start_html(-title=>'Price guide')); print($q->start_form()); # Display num1 and operations for num1. print('First number: '); if (defined($num1)) { print($num1, $q->hidden(-name=>'num1', -default=>$num1)); print(' '); print($q->submit(-name=>'clear_num1', -value=>'Clear'); } else { print($q->textfield(-name=>'num1')); } print($q->br); # Display num2 and operations for num2. print('Second number: '); if (defined($num2)) { print($num2, $q->hidden(-name=>'num2', -default=>$num2)); print(' '); print($q->submit(-name=>'clear_num2', -value=>'Clear'); } else { print($q->textfield(-name=>'num2')); } print($q->br); print($q->submit()); # End HTML. print($q->end_form()); print($q->end_html());