sub write_batch {
	my $self = shift;
	my $q = $self->query();
	
	my %batch_info;	
	my $batch_id = $q->param('batch_id');
	my $batch = Grewt::Batch->retrieve($batch_id);

	my $do_entry = $q->param('entry_flag');

	my @studies = Grewt::Study->retrieve_all;
	my %study_ref;
	my %by_study;
	
	my @add_tubes;
	my @del_tubes;
	
	my @btests = Grewt::BatchTest->search(batch => $batch_id);
	
	


	my @old_tubes = Grewt::BatchTube->search(batch => $batch_id);

	my @new_tubes = $q->param('assigned');
	
	#Need to do two loops to determine 1.What has been added and
	#2.What has been removed.
	
	#Loop through tubes in 'assigned' list
	foreach my $ntube (@new_tubes) {
		my $found = "no";
		#Loop through existing tubes
		foreach my $otube (@old_tubes) {
			#If we already have this tube in the list
			if ($otube->tube->number eq $ntube) {
				#Then set a flag
				$found = "yes";
			}
		}
		#If this tube is newly added to the batch
		if ($found eq "no") {
			#Then put it on the list to be inserted into the table
			push @add_tubes , $ntube;
		}
		#Either way, we want to pass its information on to the template
		push @{ $batch_info{$ntube->study->id} }, $tube;
	}

	#Loop through the existing tubes
	foreach my $otube (@old_tubes) {
		my $found = "no";
		#Loop through the list of assigned tubes
		foreach my $ntube (@new_tubes) {
			#If it's still in the list
			if ($otube->tube->number eq $ntube) {
				#Then set a flag to leave it alone
				$found = "yes"
			}
		}
		#If it's been removed from the list
		if ($found eq "no") {
			#Then add it to the list of tubes to be deleted
			push @del_tubes , $otube->tube->number;
		}
	}
	
	#Loop through tubes to be deleted
	foreach my $del (@del_tubes) {
		Grewt::BatchTube->search(batch => $batch_id, tube => $del)->delete_all;
		#BatchRegistry will auto-cascade, I hope.
		
	}
	
	#Loop through tubes to be added
	foreach my $add (@add_tubes) {
		my $tube = Grewt::Tube->retrieve($add);
		my $new_bt = Grewt::BatchTube->insert(	{
							batch		=>	$batch_id,
							tube		=>	$add
							});
		$new_bt->update;
		
		#Now insert into the BatchRegistry table
		foreach my $btest (@btests) {
			my $new_reg = Grewt::BatchRegistry-> insert(
							{
							batch_test 	=>	$btest,
							batch_tube	=>	$new_bt
							});
			$new_reg->update;
		}
		
	}
	
	# If the user chose to go on and enter data, pass them to the create_entry rm
	if ($do_entry eq "true") {
		return $self->redirect(
		"http://helpdesk.gentris.com/cgi-bin/Grewt.pl?rm=create_entry&batch_id=$batch_id");
	}
	prep_batch_sets(\%study_ref,\%by_study,$batch);
	return $self->tt_process('edit_batch_sets.tmpl',	{
								batch		=>	$batch,
								tlist		=>	\%by_study,
								batch_info	=>	\%batch_info,
								sref		=>	\%study_ref,
								});			

}