teste.php

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/>
        <title>Teste PHP</title>
    </head>
    <link rel="shortcut icon" href="favicon.ico" />

    <body bgcolor="#00FFFF">
        <h1 align="center">Teste PHP</h1>
        <?php
                  function soma($x, $y) {
                       $sum=$x + $y; return $sum;
   }
                 //Programa principal
                 echo 'A soma de 5 e 4 é ' . soma(5, 4);
        ?>
    </body>

</html>