Multiple default values in a multiple select list

Hi! gpk;

I explain how I have done. However, my functions are not yet finished. Since I put it on the forum, if someone knows how I can optimize the queries because I do a number of queries and I imagine that Drupal has a better system for obtaining information from the db, that I don't know yet.

I am preparing a node module. This module has its own table with fields {node_name} but also have another table with fields of selects {node_name_selects}, save when the user selects. The name of the field in the db save in a column called sid (select id), also vid, nid, and tid (for my taxonomy).

This is my form field:

$form['group1']['country'] = array(
			'#type' => 'select',
			'#title' => t('Countries'),
			'#required => TRUE,
			'#multiple' => TRUE,
			'#description' => t('Please identify the country'),
			'#options' => list_of_categories($voc = 'Countries'),
			'#default_value' => default_list($list = 'country',$node_name = 'case_type'),
			'#size' => 10,
			'#ahah' => array(),
		);

Thats my function:

function list_of_categories($voc){
	$result1 	= db_query("SELECT vid FROM {vocabulary} WHERE name = '%s'", $voc);
	$voc_id 	= db_result($result1);
	$result2 	= db_query("SELECT name, tid FROM {term_data} WHERE vid = '%d' ORDER BY tid ASC", $voc_id);
	$hijos = array();
	$papas = array();
	while ($row = db_fetch_array($result2)) {
		$id_row = $row['tid'];
		$result4 	= db_query("SELECT parent FROM {term_hierarchy} WHERE tid = '%s' ORDER BY parent ASC", $id_row);
		$parent_row	= db_result($result4);
		if($parent_row == 0){
			$papas[$id_row]['name'] = $row['name'];
		}
	}
	$result2 	= db_query("SELECT name, tid FROM {term_data} WHERE vid = '%d' ORDER BY tid ASC", $voc_id);
	while ($row = db_fetch_array($result2)) {
		$id_row = $row['tid'];
		$result4 	= db_query("SELECT parent FROM {term_hierarchy} WHERE tid = '%s' ORDER BY parent ASC", $id_row);
		$parent_row	= db_result($result4);
		if($parent_row > 0){
			$name = $papas[$parent_row]['name'];
			$child_name = $row['name'];
			$hijos[$name][$id_row] = $child_name;
		}
	}
	return $hijos;
}

I have another functions that returns diferent types of array. All of this functions need a variable with the name of the vocabulary that I want to show:

This is a function that returns a list of parent terms selectable and child terms with a sign:

function list_of_types($voc){
	$result1 	= db_query("SELECT vid FROM {vocabulary} WHERE name = '%s'", $voc);
	$voc_id 	= db_result($result1);
	$result2 	= db_query("SELECT DISTINCT name, tid FROM {term_data} WHERE vid = '%d' ORDER BY tid", $voc_id);
	$values 	= array();
	while ($row = db_fetch_array($result2)) {
		$id_row = $row['tid'];
		$result4 	= db_query("SELECT parent FROM {term_hierarchy} WHERE tid = '%s' ORDER BY parent ASC", $id_row);
		$parent_row	= db_result($result4);
		if($parent_row == 0){
			$values[$row['tid']] = $row['name'];
		}else{
			$values[$row['tid']] = '- '.$row['name'];
		}
	}
	return $values;
}

This is another functions that returns only parent terms like selectable:

function list_of_papas($voc){
	$result1 	= db_query("SELECT vid FROM {vocabulary} WHERE name = '%s'", $voc);
	$voc_id 	= db_result($result1);
	$result2 	= db_query("SELECT name, tid FROM {term_data} WHERE vid = '%d' ORDER BY tid ASC", $voc_id);
	$papas = array();
	while ($row = db_fetch_array($result2)) {
		$id_row = $row['tid'];
		$result4 	= db_query("SELECT parent FROM {term_hierarchy} WHERE tid = '%s' ORDER BY parent ASC", $id_row);
		$parent_row	= db_result($result4);
		if($parent_row == 0){
			$parent_name = $row['name'];
			$papas[$id_row] = $parent_name;
		}
	}
	return $papas;
}

And this returns the list of my vocabulary.

function list_of_vocabulary(){
	$result1 	= db_query("SELECT name FROM {vocabulary}");
	$list = db_fetch_array($result1);
	return $list;
}

The function that returns me an array with default values are that follows:

function default_list($list, $node_name){
	$result1 	= db_query("SELECT tid FROM {".$node_name."_selects} WHERE sid = '%s'", $list);
	$default_values = db_fetch_array($result1);
	return $default_values;
}

This function needs the name of vocabulary ($list) and the name of the node (my type of content, $node_name).

I suppose that can be improved, if you want to collaborate on what would help. However, my main concern right now is that I return the default values that I ask, namely that I have in the database.

Thanks for your answers and patience.