View on the next page - php

Question

Right guys here is my big ass question, I'm just a begginer and all of that so it's probably just a silly and easy thing but how from this code
<?php
session_start();
if(!isset($_SESSION['password']))
{
header('Location:index.php');
exit();
if ($_SESSION['logged_in']= 0)
{
header('Location:index.php');
exit();
}
}
?>
<?php include 'includes/header.php';?>
<div class="page_menu_box">
<ul>
<li>USER PROFILE</li>
<li>ABOUT US</li>
</ul>
</div>
<div class="page_content">
<table class="viewbook_table">
<tr>
<th>ISBN</th>
<th>AUTHOR</th>
<th>DATE WHEN PUBLISHED</th>
<th>COVER</th>
</tr>
<?php
include("core/database/connect.php");
$connection = #new mysqli('localhost','root','','bs_admin_tools');
$sql = "SELECT * FROM books";
$query = $connection->query( $sql );
while ($row = mysqli_fetch_array($query))
{
echo "<tr>";
echo "<td width = 15%>";
echo $row['ISBN'];
echo "</td>";
echo "<td width = 15%>";
echo $row['author'];
echo "</td>";
echo "<td width = 15%>";
echo $row['datepublished'];
echo "</td>";
//check whether an image is available for the record chosen
if ( $row['imgdir'] )
{
//create a variable which holds data from the images folder
$imageDir = "image/";
//create a second variable which holds the value of the image linked to the record selected
$img = $imageDir . $row['imgdir'];
/*link to the directory*/
echo "<td width ='15%' padding='30%'>";
//display the image
echo "<left><a href='viewdetails'><img src='$img'></a>";
echo "</td></tr>";
}
//echo "<br />"; //display a line break
}//end of the while loop
//release connection from database
mysqli_close($connection);
?>
</table>
</div>
<?php
echo "<div class='page_menu_box'><ul><li>
".$_SESSION['login']."
</ul></li></div>'";
include 'includes/footer.php';?>
I just want to basically click on the $img and view the book details, in other words I make one of the variables into a hyperlink and whenever someone is transferred onto another page I want a variable to be sended to that file where I would facilitate the file to intake the variable and display other shit about that book using 'Select from books where $theVariable="XD"'. I would be really happy if anyone could help me, I'm bouncing my head over a wall for the 2nd day to work that out.
I can only do stuff on php so please solutions only involving php or html ;_;