function _buildTree($data, $idParent, $indentSymbol, $level)
{
$cat = array();
foreach($data as $row){
if($row['parent_id'] == $idParent){
if($indentSymbol AND $level > 0){
$symbols = array_fill(0, $level, $indentSymbol);
$cat[$row['id']] = implode('', $symbols) . $row['name'];
}else{
$cat[$row['id']] = $row['name'];
}
$cat = $cat + _buildTree($data, $row['id'], $indentSymbol, $level++);
}
}
return $cat;
}
$result = mysql_query("SELECT * FROM cats");
$data = array();
while($row = mysql_fetch_assoc($result)){
$data[] = $row;
}
$select = '<select>';
foreach(_buildTree($data, 0, '-', 0) as $key=>$option){
$select .= '<option value=' . $key . '>' . $option . '</option>';
}
$select .= '</select>';