Use the trim function to remove blank spaces

PLEASE MAY SOMEONE HELP

<?php session_start(); $word1 = htmlspecialchars($_SESSION['word'][1]); $word2 = htmlspecialchars($_SESSION['word'][2]); $word3 = htmlspecialchars($_SESSION['word'][3]); $word4 = htmlspecialchars($_SESSION['word'][4]); $word5 = htmlspecialchars($_SESSION['word'][5]);

for($i=1; $i<= 5; $i++){ if(empty(trim($_SESSION['word'][$i]))){ if($i==1){ header('location:play.php'); exit; } else{ header('location:play.php?p='.$i); exit; } } }

include 'inc/header.php';

for ($word =1; $word <=5; $word++) { if(!isset($_SESSION['word'][$word])) { header('location:play.php?p=' . $word); exit; } }

echo '<h1>My Treehouse Story</h1>';

echo '<p>There once was a(n) ' . $word1; echo ' programmer named ' . $word2; echo '. </p>'; echo '<p>This ' . $word3; echo ' programmer used Treehouse to learn to ' . $word4; echo ' the ' . $word5 . '.</p>';

echo ' <a class="btn btn-default btn-lg" href="#" role="button">Save Story</a>'; echo ' <a class="btn btn-default btn-lg" href="play.php" role="button">Play Again</a>'; echo ' <a class="btn btn-default btn-lg" href="index.php" role="button">Other Stories</a>';

include 'inc/footer.php'; ?>

<?php session_start(); 
$word1 = htmlspecialchars($_SESSION['word'][1]); 
$word2 = htmlspecialchars($_SESSION['word'][2]); 
$word3 = htmlspecialchars($_SESSION['word'][3]); 
$word4 = htmlspecialchars($_SESSION['word'][4]); 
$word5 = htmlspecialchars($_SESSION['word'][5]);

for($i=1; $i<= 5; $i++){ if(empty(trim($_SESSION['word'][$i]))){ if($i==1){ header('location:play.php'); 
   exit; } 
   else{ header('location:play.php?p='.$i); 
        exit; 
                     }
             }
          }

include 'inc/header.php';

for ($word =1; $word <=5; $word++) {
  if(!isset($_SESSION['word'][$word])) {
    header('location:play.php?p=' . $word);
    exit;
  }
}


echo '<h1>My Treehouse Story</h1>';

echo '<p>There once was a(n) ' . $word1;
echo ' programmer named ' . $word2; 
echo '. </p>';
echo '<p>This ' .  $word3; 
echo ' programmer used Treehouse to learn to ' . $word4;
echo ' the ' . $word5 . '.</p>';

echo ' <a class="btn btn-default btn-lg" href="#" role="button">Save Story</a>';
echo ' <a class="btn btn-default btn-lg" href="play.php" role="button">Play Again</a>';
echo ' <a class="btn btn-default btn-lg" href="index.php" role="button">Other Stories</a>';


include 'inc/footer.php';
?>