Code for a simple multi-level tree menu

//Tree directory structure template program
//Menu directory library field description:
//menu_id menu item id
//menu menu name
//menu_grade menu level 1 is the main menu 2 is the secondary menu...
//menu_superior The id number of the previous menu
function my_menu($menu_content,$i,$menu_grade_temp,$ menu_superior_temp)
{
global $PHP_SELF;
$temp1=$menu_grade_temp+1;
$menu_superior_temp_array=split("/",$menu_superior_temp);
for ($t=0;$t<$i;$t++)
 {
$menu_array=split("/",$menu_content[$t]);
If(($menu_array[2]==$menu_grade_temp)&&($menu_array[3]==$menu_superior_temp_array[$menu_grade_temp-1] ))
{
for($p=1;$p<=$menu_grade_temp;$p++){echo " ";}
$temp3=$menu_superior_temp_array;
$temp3[$menu_grade_temp]=$menu_array[0];
 $temp2=implode("/",$temp3);
if ($menu_array[0]==$menu_superior_temp_array[$temp1-1])
{
$temp5=$temp1-1;
$temp3[$menu_grade_temp] ="";
$temp6=implode("/",$temp3);
echo "$menu_array[1] ";
my_menu($menu_content,$i,$temp1,$temp2);
}
else
{
$temp3[$menu_grade_temp+1]="";
$temp6= implode("/",$temp3);
echo "$menu_array[1]}
}
}
}
// Connect to MySql database
$db_host="localhost";
$db_user="dkj";
$db_password="123";
$db_name="test";
 mysql_connect($db_host,$db_user,$db_password);
mysql_select_db($db_name);
//Get data from the database
$query_string="select * from menu order by menu_grade";
$db_data=mysql_query($query_string);
//First execution of initialization
if ($menu_grade_temp=="")
{
$menu_superior_temp=0;
}
//Read all the information into the array and count the number of arrays
$i=0;
while (list($menu_id,$menu,$menu_grade,$menu_superior)=mysql_fetch_row($db_data ))
{
$menu_content[$i]=$menu_id."/".$menu."/".$menu_grade."/".$menu_superior;
$i++;
}
my_menu($menu_content,$i ,1,$menu_superior_temp);
/* Attached database structure and simulation data
# Host: localhost Database: test
# Data table structure 'menu'
CREATE TABLE menu (
menu_id int (11) NOT NULL auto_increment,
menu varchar(20) NOT NULL,
menu_grade int(11) NOT NULL,
menu_superior int(11) NOT NULL,
UNIQUE menu_id (menu_id)
);
< ;p># Export the following database content 'menu'
INSERT INTO menu VALUES( '1', 'Computer', '1', '0');
INSERT INTO menu VALUES( '2', 'Programming', ' 2', '1');
INSERT INTO menu VALUES( '3', 'Network', '2', '1');
INSERT INTO menu VALUES( '4', 'PHP and MySql', '3' , '2');
INSERT INTO menu VALUES( '5', 'C language', '3', '2');
INSERT INTO menu VALUES( '6', 'Web page production', '3', ' 3');
INSERT INTO menu VALUES( '7', 'TCP, IP protocol', '3', '3');
INSERT INTO menu VALUES( '8', 'Math', '1', '0 ');
INSERT INTO menu VALUES( '9', 'Advanced Mathematics', '2', '8');
INSERT INTO menu VALUES( '10', 'Linear Algebra', '3', '9') ;
INSERT INTO menu VALUES( '11', 'Discrete Mathematics', '3', '9');
INSERT INTO menu VALUES( '12', 'Elementary Mathematics', '2', '8');
 INSERT INTO menu VALUES( '13', 'Literature', '1', '0');
INSERT INTO menu VALUES( '14', 'Programmer's Home', '2', '13');
INSERT INTO menu VALUES( '15', 'php', '4', '4');
INSERT INTO menu VALUES( '16', 'mysql', '4', '4');
*/
?> ;