How to associate query with changing variable in PHP - php

Question

I'm in need of a bit help. I'm trying to find out how to associate a specific query (deletion of a record) with not the id of a record, but the record with which another query (selection of a record) is echoed out.
This line of code totally works when the id is specified, but again I need it for the record that gets called, where the id can skip numbers if I delete a record.
$querytwo = "DELETE FROM `paginas` WHERE id = 5";
I've got a table in my phpmyadmin database with columns 'id', 'pagetitle', 'toevoeging' (addition in Dutch) , 'message'. First one is an INT, rest are varchars/text.
This may be a stupid question, I'm sorry for that. I'm still new to PHP, and to programming in general.
Here is the code. I've commented on lines code to clarify. Thanks you!.
<?php
if (isset($_SESSION['email'])) //if the admin is active, forms can be written out.
{
echo '</nav>
<br><br> <div class="inlogscript">
<form action="verstuurd.php" method="post">
<input type="text" placeholder="Titel" method="POST" name="pagetitle" /><br><br>
<input type="text" placeholder="Toevoeging" method="POST" name="toevoeging" /><br><br>
<textarea class="pure-input-1-2" placeholder="Wat is er nieuws?" name="message"></textarea><br>
<input type="submit" value="Bevestigen" />
</form></div>';
}
?>
<div class="mainContent">
<?php
include_once("config.php"); //this is the database connection
$query = "SELECT * FROM paginas "; //selects from the table called paginas
$result = mysqli_query($mysqli, $query);
while($row = mysqli_fetch_assoc($result))
{
$pagetitle = $row['pagetitle'];
$toevoeging = $row['toevoeging'];
$message = $row['message'];
echo '<article class="topcontent">' . '<div class="mct">' . '<h2>' . "$pagetitle" .'</h2>' . '</div>' . "<br>" .
'<p class="post-info">'. "$toevoeging" . '</p>' . '<p class="post-text">' . '<br>'. "$message" . '</p>' .'</article>' . '<div class="deleteknop">' . '<form method="post">
<input name="delete" type="submit" value="Delete Now!">
</form>' . '</div>' ;
} //This long echo will call variables $pagetitle, $toevoeging and &message along with divs so they automatically CSS styled,
//along with a Delete button per echo that has the 3 variables
$querytwo = "DELETE FROM `paginas` WHERE id = 5";
if (isset($_POST['delete'])) //Deletes the query if 'delete' button is clicked
{
$resulttwo = $mysqli->query($querytwo);
}
?>
</div>
</div>
Also here is the Insert INTO query of the records. Thanks again!
$sql = "INSERT INTO paginas (pagetitle,toevoeging, message)
VALUES ('$_POST[pagetitle]','$_POST[toevoeging]','$_POST[message]')";
//the insertion into the table of the database
if ($MySQLi_CON->query($sql) === TRUE) {
echo "";
} else {
echo "Error: ". $sql . "" . $MySQLi_CON->error;
}

Answer 1

This won't be sufficient but, to begin with your echo :
echo '<article class="topcontent">
<div class="mct">
<h2>' . $pagetitle .'</h2>
</div><br>
<p class="post-info">'. $toevoeging . '</p>
<p class="post-text"><br>'.$message.'</p>
</article>
<div class="deleteknop">
<form method="post">';
// you ll want to use $_POST["id"] array to delete :
echo '<input type="hidden" name="id" value="'.$row['id'].'">
<input name="delete" type="submit" value="Delete Now!">
</form>
</div>' ;