<?php
switch ($condition):
case $value:
do_something();
break;
default:
do_something_else();
break;
endswitch;
?>
<?php switch ($condition): ?>
<?php case $value: /* having whitespace before your cases will cause an error */ ?>
<p>Do something in HTML</p>
<?php break; ?>
<?php default: ?>
<p>Do something else in HTML</p>
<?php break; ?>
<?php endswitch; ?>