Prueba asi:
Código PHP:
$campos_obligatorios = array(
"name"=>"<p>You need to write your name in order to create your account</p>",
"surname"=>"<p>You need to write your surname in order to create your account</p>",
"password"=>"<p>You need a password to create your account</p>"
);
$f = 0;
foreach($campos_obligatorios as $campo=>$error) {
$val = trim($_POST[$campo]);
if(empty($val)) {
echo $error;
$f = 1;
}
}
if($f == 0) {
echo "Registration completed. <br /> <a href='login.html'>Begin</a> <br />";
}
Un saludo,