sub doNavigation {
  my $root = $_[0];
  my $select = "f2c_id,f2c_fatherid";
  my $from = "t_father2child";
  my $where = "f2c_id = $root";
  my @fathers = doSelect($select,$from,$where); 
  my $fatherId = $fathers[0][1];
  loop($root,$fatherId);
} # end sub

sub loop {
  my $root = $_[0];
  my $father = $_[1];
  my $select = "f2c_id,f2c_fatherid,f2c_childid,element_titel";
  my $from = "(t_father2child INNER JOIN t_element ON f2c_ChildId = element_id)";
  my $where = "f2c_fatherid = $father AND f2c_NodeTypeId = 1";
  my @nodes = doSelect($select,$from,$where); 
  foreach my $node (0..$#nodes) {
	print "<br><a href=?node_id=$nodes[$node][0]> - $nodes[$node][1] - $nodes[$node][2] - $nodes[$node][3]</a>";
	if ($nodes[$node][0] == $root) {
	  my $select = "f2c_id,f2c_fatherid,f2c_childid,element_titel";
	  my $from = "(t_father2child INNER JOIN t_element ON f2c_ChildId = element_id)";
	  my $where = "f2c_fatherid = $nodes[$node][2] AND f2c_NodeTypeId = 1";	
	  my @children = doSelect($select,$from,$where); 
	  if (@children) {
		loop($root,$children[0][1]);
	  } # end children-if
	} # end node-if
 } # end node-foreach
}