Open your PHP template and save it as phpifelse.php.

Adding an else (just like in JavaScript) allows you to choose what will happen using a condition with different code running if the condition is true or false:

if ($firstvalue==$secondvalue) {
    echo "<p>the values are the same</p>";
} else {
    echo "<p>the values are different</p>";
    echo "<p>sorry about that</p>";

Try that with different values in the first two lines.