<body>
<h1>???????</h1>
<h3>form006.php ?????????????</h3>
?????????????????<br>
<?php
$no = $_GET['suu'];
$kotae = 0;
if($no ==NULL){
echo "????????????<br />";
}else{
for($i=0;$i <= $no;$i++){
$kotae += $i;
}
echo "?" .$no . "??????<b>" . number_format($kotae) . "</b>??<br />";
}
?>
<br />
<form action="form006.php" method="get">
???????????<br />
<input type="text" name="suu" />
<input type="submit" value="??" />
</form>
</body>
</html>