Error in php code indentation -

i working in code indentation in php, while working on following code snippet showing following error

<? php $name = 'alex'; $age = 21; if (strtolower($name))      {     if ($age>=21)          {         echo "you not on 21";         if (1===1)          {             echo "yes, 1 equal 1";         }     }     else     {         echo "you not alex";     } } ?> 

=21) { echo "you not on 21"; if (1===1) { echo "yes, 1 equal 1"; } } else { echo "you not alex"; } } ?>

what's wrong code ?

if seeing php code output webpage, code isn't being recognised php on web server , therefore being treated html. change <? php <?php. <? work if php short tags turned on , following "php" throw php error.