# initiate instance 
my $in = CGI->new(); 
  
  
# create a sample delimited line 
my $templine = '1~~3~~6~~9'; 
  
# simple array 
my @fields = ( 1 .. 15 ); 
  
# create array of items split on ~~ 
my @checked = split( /~~/, $templine ); 
  
  
# let cgi.pm know the values that should already be checked. 
$in->param( 'test' => @checked ); 
  
# output new checkbox group. 
print $in->checkbox_group( 
        -name      => 'test', 
        -values    => \@fields, 
        -linebreak => 1 
);