ต้องการเขียน code php ให้แสดงภาพตามช่วงตัวเลขที่กำหนด

$sql=mysql_query("select * from table");
$row=mysql_fetch_array($sql);
$num=$row['number'];
if($num<=40){
   echo "<img src='001.gif'>";
}else if($num<=70){
   echo "<img src='002.gif'>";
}else if($num<=100){
   echo "<img src='003.gif'>";
}

	$score=$row['number'];

	echo 'Score is ', $score;

	if ($score<36) {
		echo "<img src='img/01.gif'>";
	} else if ($score<=37.9) {
		echo "<img src='img/02.gif'>";
	} else if ($score<=40) {
		echo "<img src='img/03.gif'>";
	} else if ($score<=44) {
		echo "<img src='img/04.gif'>";
	} else if ($score<=44.5) {
		echo "<img src='img/05.gif'>";
	} esle {
		echo "<img src='img/06.gif'>";
	}

$number = (int) 50;

if ($number <= 100) $img = '03.gif';
if ($number <= 70) $img = '02.gif';
if ($number <= 60) $img = '01.gif';

echo $img;