#!/usr/local/bin/perl 
#
# Example 4-3. biopage.cgi

use GD;
use CGI;

# First get the parameters passed into the script
# Use the CGI module to parse the CGI form submission.

my $q = new CGI;
my $dob = $q->param('dob'); 
my $start = $q->param('start');
my $end = $q->param('end');

# Use the CGI module to create the HTML for the page
# Print the header and opening tags

print $q->header(-type => 'text/html');
print $q->start_html(-title => "Biorhythm!");

if ($dob && $start && $end) {

    # Output the html for the image tag. This passes the data 
    # on to the bio.cgi script to generate the image data. 

    print $q->h1("Your biorhythm from $start to $end");
    print $q->img({ src => "biorhythm.cgi?".
                           "dob=$dob&start=$start&end=$end",
                    width => 500, height => 300 });
    print $q->br;

} else {

    # In this case, no data has been passed to the script; this 
    # may be because this is the first invocation of the script or
    # blank fields were submitted. We can just print an 
    # appropriate headline...

    print $q->h1('Get your biorhythms here!');
}

# Print the form used to enter the dates

print $q->start_form({ method => 'post',
                       action => 'biopage.cgi' }),
      
      "Date of Birth:",
      
      $q->input({ type => 'text',
                  name => 'dob',
                  size => 10,
                  value => $dob }),
    
      "Calculate biorhythms from  ",
      
      $q->input({ type => 'text',
                  name => 'start',
                  size => 10,
                  value => $start }), 
      " to ",
      
      $q->input({ type => 'text',
                  name => 'end',
                  size => 10,
                  value => $end }),
      $q->input({ type => 'submit',
                  value => 'Give me my biorhythm!' }),
      $q->end_form(),
      $q->end_html();