Php Repeatable region - php

Question

So i got this code, at the moment it is repeating everything , and i just wanted it to repeat the echo, so i get all usernames from it, if i leave it as it is it will also repeat the form when i press a username. Every time i tried to ajust it, it just gave me syntax errors
<?php do { ?>
<?php
$username = $row_mensagens['username'];
$user = $row_mensagens['id'];
if(isset($_GET['user']) && !empty($_GET['user'])){
?>
<form>
Introduz mensagem : <br>
<textarea name='message' rows='7' cols='60'></textarea>
<br><br>
<input type='submit' value="Send Message" />
</form>
<?php
} else {
echo "<p><a href='mensagens.php?user=$user'>$username</a></p>";
}
?>
<?php } while ($row_mensagens = mysql_fetch_assoc($mensagens)); ?>

Answer 1

that do { } while() will always repeat as many as the number of records come from database.
You can do it this way:
<?php
if(isset($_GET['user']) && !empty($_GET['user'])){
?>
<form>
<input type="hidden" name="user" value="<?php echo $_GET['user']; ?>" /> <!-- hidden field so you can process to who -->
Introduz mensagem : <br>
<textarea name='message' rows='7' cols='60'></textarea>
<br>
<br>
<input type='submit' value="Send Message" />
</form>
<?php
} else {
do {
$username = $row_mensagens['username'];
$user = $row_mensagens['id'];
echo "<p><a href='mensagens.php?user=$user'>$username</a></p>";
} while ($row_mensagens = mysql_fetch_assoc($mensagens));
}
?>
Move do { inside else and show the form only if you have a $_GET['user']
I have also added for you a hidden field, so you know who to send message.
Hope you understand how this works. Documentation on Control Structures: do-while
I also suggest to make that form a post form, as by default it is a get form, and since you have a textarea you are more likely to bump into errors if the message is too long.
LE: Another suggestion, try to move to PDO or mysqli_* functions since mysql_* functions are considered deprecated as of PHP 5.5 and have some good chances to be removed.