<!DOCTYPE html>
<html>
<head>
<title>Inches to Centimeters Converter</title>
</head>
<body>
<?php
// One inch is 2.54 cm.
$one_inch = 2.54;
// My screen has a size of ... inches.
$size_in_inches = $_GET['size'];
// Perform conversion and display result.
$size_in_cms = $size_in_inches * $one_inch;
echo "<p>Your screen measures $size_in_cms centimeters.";
?>
</body>
</html>