PHP:

<div class=shadow-box>
  <h3 class=title style=font-size:20px>
  <?php 
    if($pet["pet_cat"] == 2):
  ?>
  <?php 
    echo $pet["pet_name"];
  ?>
   <?php 
      else:
  ?>
  <?php 
      echo "Please Help me";
   ?>
   <?php endif;
   ?>
   </h3>
   <p class=subtitle>
   <?php 
     if($pet["pet_cat"] == 2):
    ?>
    <?php
       echo $pet["english"];
    ?>
    <?php 
        else:
    ?>
    <?php 
       echo $pet["dog_english"];
     ?>
     <?php 
        endif;
      ?>
      <div class=image>
      <a href=<?php
                  echo base_url();
              ?>index.php/Pet/view/<?php echo $pet["petid"];?> id=listinglink target=_blank><img src=<?php $img = unserialize($pet["img"]); echo base_url();?>assets/img/<?php echo $pet["pet_hidenum"]."/".$img[0]?> class=img-responsive id=centerimg></a></div><div class="clearfix quick-info"><div class=left><p><span class=icon style=font-size:12px><img src=images/location.png alt=""></span><?php echo $pet["reg_postal"].",".$pet["reg_city"].",".$pet["reg_country"]?><?php if($pet["showtel"] == "Yes"):?><p><span class=icon><img src=images/phone.png alt=""></span><?php $mobile_phone_number = unserialize($pet["mobile_phone_number"]); echo $mobile_phone_number[0];?><?php endif;?><?php if($pet["pet_type"] == "Lost"):?><p id=rewardon><span class=icon><img src=images/reward.png alt=""></span>Reward:€ (EUR)</div><?php endif;?><div class=right><p style=margin-top:14px><img src=images/mini_logo.png alt=""style=width:95px><p>37070 Days Ago</div></div></div>

Error:

Use of undefined constant php - assumed 'php'

Why is it displaying error Use of undefined constant? I checked twice but I did not find anything wrong in my code. Your help is appreciated...............