<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"
http://www.w3.org/TR/html4/strict.dtd 
">
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>untitled</title>
<meta name="generator" content="TextMate
http://macromates.com/ 
">
<meta name="author" content="anop72">
<!-- Date: 2011-01-20 -->
</head>
<?
$x = $_GET['var1'];
$y = $_GET['var2'];
$ans = $x+$y;
?>
<body>
<form action="untitled.php" method="get">
<input type="text" name="var1" />
<input type="text" name="var2" />
<input type="text" name"ans" value="<?=$ans?>"/>
<input type="submit" name="add" />
</form>
</body>
</html>
save เป็นชื่อไฟล์ untitled.php