#!/usr/bin/perl

# ... code deleted here ...

if (@errors = &areErrors) {
    &printErrors;
} else {
    &finishAndExit;
}

# Check that the value of the *required* CGI parameter
# "price" is indeed numeric. If not, push a message
# onto the @ERRORS array.

sub areErrors {
  my @ERRORS;
  if (!$query->param('price')
   && ($query->param('price') !~ /^0+$/)) {
    # The call to param() for the 'price' evaluated to
    # false, and it also wasn't just a string of zeroes.
    push @ERRORS, "'price' is a required numeric value.";
  if ($query->param('price') !~ /^\d+$/) {
    # There were characters other than digits here.
    push @ERRORS, "'price' must be a numeric value.";
  }
  return @ERRORS;
}

# Output an HTML unordered list, with each list item
# being an error from the @ERRORS array.

sub printErrors {
  my @ERRORS = @_;
  my $error;
  print "<h2>Errors in your input:</h2>\n";
  print "<ul>\n";
  foreach $error (@ERRORS) {
    print "<li>", $error, "\n";
  }
  print "</ul>\n";
}