When I click on the more details link og the detail.php page the link appears to work ok, however, the id doesn't appear to attach on to the query string. The result is further_detail.php?detail_id=

The id doesn't appear to attach on, leaving a blank page where the further details should appear.

I'd be grateful if anyone could check if I am missing something here

detail.php

Code:
echo "<a href=\"further_detail.php?detail_id=";
echo $row['detail_id'];
echo "\">More Details</a>";
further_detail.php

Code:
$id = $_GET['detail_id'];

$result=mysql_query("SELECT firstname,lastname, address1 FROM tblDetail
WHERE detail_id = '$id'") or die(mysql_error());

while($row = mysql_fetch_array( $result )) {
echo "<table style = \"margin-top:20px;\">";	
	echo "<tr>";
	echo "<td>Name:</td>";
	echo "<td>";
	echo $row['firstname']." ".$row['lastname'];
	echo "</td>";
	echo "</tr>";
	echo "<tr>";
	echo "<td>Address:</td>";
	echo "<td>";
	echo $row['address1'];
	echo "</td>";
	echo "</tr>";
echo "</table>";
}