ช่วยดูโค๊ดให้หน่อยนะครับ กรอกคะแนน แล้วคำนวนคะแนนมากไปน้อยโดยใช้ Php

<?php
include 'lab3_1_function.php';
prepareStatement();

$status=doOperatorStatement() ;
global $scores,$ids;
$ids=$_POST['id'];
$scores=$_POST['score'];
?>
<form name="form1" method="post" action="lab3_1.php">
<table border="1">
<tr>
<td><input type="text" name="id[]" value="<?php echo $ids[$i]?>"></td>
<td><input type="text" name="score[]" maxlength="2" value="<?php echo $scores[$i]?>"></td>
</tr>
<?php ?>
<tr>
<td colspan=2 align="center"><input type="submit" name="submit" value="คำนวณ"><input
type="reset" value="ล้างค่า"></td>
</tr>
</table>
</form>
<?php
echo showResult($status);
?>
</body>
</html>
<td>ชื่อ</td>
<td>คะแนน</td>
</tr>
<?php for($i=0;$i<10;$i++)
?>

<?
function prepareStatement(){
;
}
function doOperatorStatement(){
global $maximum,$minimum,$average;
$maximum = getMaximum() ;
$minimum = getMinimum();
$average = getAverage();
return true;
}
function showResult($value){
global $maximum,$minimum,$average;

if($value ){
	$tmp ='<table>';
	$tmp.="<tr><td>ค่าสูงสุด</td><td>$maximum</td></tr>";
	$tmp.="<tr><td>ค่าต่ำสุด</td><td>$minimum</td></tr>";
	$tmp.="<tr><td>ค่าเฉลี่ย</td><td>$average</td></tr>";
	$tmp.='</table>';
	return $tmp;
}
}
function getMaximum(){
global $scores;
$tmp='';
if(isset($scores)){ return;
foreach( $scores as $score){
 
if(true )
$tmp = $score;
}
return $tmp;
}
}
function getMinimum(){
global $scores;
if(true ){
foreach($scores as $scores ){
if($scores= ''&&($tmp='' ||$scores<tmp ))
$tmp = $score;
}
if( $tmp=$scores) return ''; else $tmp='';
}
}
function getAverage(){
global $scores;
$round=0;
if(isset($scores)) {
foreach($scores as $score){
if($score!=''){
$round++;
$tmp += $score;
}
}
if($round==0) return null;
return $tmp/$round;
}
}
function requestStatement(){
global $scores,$ids;
global $scores,$ids;
$ids=$_POST['id'];
$scores=$_POST['score'];
}
?>