What I'm doing wrong?

I want to print a random sentence everywhere the page is loaded, this is very simple, I know but I'm a very noob with php, can anyone help me?

I tried to to print the html with echo function but it didn't worked.

  <?php $r = rand(1,3); ?>
  <?php if ($r==1){ ?>
    <div class="message">
    <font color="00FF22"><span class="textData" data-to-animate='[" This site as been hacked!" , " We are sorr" , " Which of these tool u want to use?"]'></span></font>
    </div>
  <?php } ?>
  <?php elseif ($r==2){ ?>
    <div class="message">
    <font color="00FF22"><span class="textData" data-to-animate='[" This site is next to be closed." , " We are sorr" , " Which of these tool u want to use?"]'></span></font>
    </div>
  <?php } ?>
  <?php elseif ($r==3){ ?>
    <div class="message">
    <font color="00FF22"><span class="textData" data-to-animate='[" The monkeys destroyed the server." , " We are sorr" , " Which of these tool u want to use?"]'></span></font>
    </div>
  <?php } ?>

I get a blank page.