Listing 1: The version of edit-quizfile that displays the form

#!/usr/bin/perl -w

use strict;
use diagnostics;
use CGI;        # Available from http://www.perl.com/CPAN
use QuizQuestions;

# Maximum index for questions (starting at 0)
my $MAX_QUESTIONS = 10;

# Create an instance of CGI
my $query = new CGI;

# Print the MIME header that we will always use
print $query->header("text/html");

# Determine how we were invoked
my $request_method = $query->request_method;

# If we were invoked via POST, then ignore things for now
if ($request_method eq "POST")
{
    print $query->start_html(-title => "Not yet implemented");
    print "<P>Sorry, the POST part of this program isn't yet written.</P>\n";
    print $query->end_html;
}
else
{
    # If the query string is empty, then produce a page of HTML
    # containing ISINDEX 
    if ($query->param("keywords") eq "")
    {
	print $query->start_html(-title => "Enter a quiz name");
	print "<P>Please enter the name of the quiz you want ";
	print "to create or edit in the below .</P>\n";
	print "<ISINDEX>\n";
	print $query->end_html;
    }
    else
    {
	# Get the name of the quiz
	my $quizname = $query->param("keywords");

	# Create a new instance of QuizQuestions
	my $questions = new QuizQuestions($quizname);

	# Read the questions from disk, ignoring errors
	# (since we will happily create a new quiz)
	$questions->loadFile;

	# Create the header for the HTML page
	print $query->start_html(-title => "Create/Edit a quiz");

	# Define a form
	my $script_name = $query->script_name;
	print "<Form method=\"POST\" action=\"$script_name\">\n";

	# Create the text element for the quiz name
	print "<P>Editing quiz: <input type=\"text\" name=\"quizname\" ";
	print "value=\"$quizname\"></P>\n";
	print "<HR>\n\n";

	# Now create one form element for each existing question
	
	my $counter = 0;
	foreach $counter (0 .. $MAX_QUESTIONS)
	{
	    # Get a particular question
	    my ($qtext, $ansA, $ansB, $ansC, $ansD, $correct)
		= $questions->getQuestion($counter);

	    # Question text
	    print "<H2>Question $counter</H2>\n";
	    print "<P>Question text: <input type=\"text\" ";
	    print "name=\"question-$counter\" value=\"$qtext\" ";
	    print "size=\"30\"></P>\n";

	    # Answer A
	    print "<P>Answer A: <input type=\"text\" value=\"$ansA\" ";
	    print "name=\"answer-a-$counter\" size=\"30\"></P>\n";

	    # Answer B
	    print "<P>Answer B: <input type=\"text\" value=\"$ansB\" ";
	    print "name=\"answer-b-$counter\" size=\"30\"></P>\n";

	    # Answer C
	    print "<P>Answer C: <input type=\"text\" value=\"$ansC\" ";
	    print "name=\"answer-c-$counter\" size=\"30\"></P>\n";

	    # Answer D
	    print "<P>Answer D: <input type=\"text\" value=\"$ansD\" ";
	    print "name=\"answer-d-$counter\" size=\"30\"></P>\n";

	    # Correct answer
	    print "<P>Correct answer: <select name=\"correct-$counter\">\n";
	    
	    my $letter = "";
	    foreach $letter ("a","b","c","d")
	    {
		print "<option ";
		print "selected " if ($letter eq $correct);
		print "$letter>$letter\n";
	    }

	    print "</select>\n";
	    print "<HR>\n\n";
	}

	# Now that the loop is complete, we can finish things up
	print '<input type="submit" value="Save changes">', "\n";
	print "</HTML>\n";
	print $query->end_html;
    }
}