Linking within the search results

hey guys,
I'm just wondering how you can link to another set of results within the original search results. For example with my code it displays a table and in one of the coloums, plot number, there is a list of number. I would know what to do once the user clicks it to find the result but what I am wondering is how to make each number in that coloum a link. And once the user clicks the link how do you make that a search variable? I'm pretty new to php so bare with me haha.

<?php
    mysql_connect ("localhost", "root","root") or die (mysql_error());
    mysql_select_db ("FHSNL");
	//sets all values in form to php variables
    $surname = $_POST['surname'];
    $given = $_POST['given'];
	$maiden = $_POST['maiden'];
	$deathdate = $_POST['death'];
	$deathbefore = $_POST['death'] - 5;
	$deathafter = $_POST['death'] + 5;
	$age = $_POST['age'];
	$birth = $_POST['birth'];
	$birthplace = $_POST['birthplace'];
	$deathplace = $_POST['deathplace'];
	$erected = $_POST['erected'];
	$region = $_POST['region'];
	$religion = $_POST['religion'];
	//divides into smaller sql pieces for filled in form input.
	if($surname)$piece[] .= "`SURNAME` LIKE '%$surname%'";
	if($given)$piece[] .= "`GIVEN` LIKE '%$given%'";
	if($maiden)$piece[] .= "`MAIDEN` LIKE '%$maiden%'";
	if($age)$piece[] .= "`AGE` LIKE '%$age%'";
	if($deathplace)$piece[] .= "`PLACE_OF_DEATH` LIKE '%$deathplace%'";
	if($region)$piece[] .= "`TOWN` LIKE '%$region%'";
	if($religion)$piece[] .= "`RELIGION` LIKE '%$religion%'";
	if($deathdate)$piece[] .= "`YEAR_OF_DEATH` BETWEEN '$deathbefore' AND '$deathafter'";
	//if submit button is pressed it runs the search query.
    if(isset($_POST['submit'])){
		if(isset($piece)){
  $sqlend = implode(" AND ",$piece);
  $sql = mysql_query("SELECT * FROM `HEADSTONESA` WHERE $sqlend");
  $rows = mysql_num_rows($sql);
  //constructs the table.
	echo "<table><tr><th>ID</th><th>Given</th><th>Surname</th><th>Cemetery</th><th>Region</th><th>Town</th><th>Date of Death</th><th>Age</th><th>Date of Birth</th><th>Place of Birth</th><th>Place of Death</th><th>Erected By</th><th>Additional Info</th>";
	while($row = mysql_fetch_array($sql))
	{
		echo "<tr>";
    echo "<td>" .$row['ID'] . "</td>";
    echo "<td>".$row['GIVEN']."</td>";
    echo "<td>".$row['SURNAME']."</td>";
	$requested_id = $row['KEYS'];
	$town_id = $row['TOWN'];
	$region_id = $row['REGION'];
	$sql2 = mysql_query("SELECT * FROM `CEMETERIES` WHERE `KEYS` LIKE '$requested_id'");
	$row2 = mysql_fetch_array($sql2);
	echo "<td>".$row2['NAME']."</td>";
	echo "<td>".$row2['REGION']."</>";
	echo "<td>".$row2['TOWN']."</td>";
    echo "<td>".$row['D_OF_DEATH']."</td>";
    echo "<td>" .$row['AGE']. "</td>";
	echo "<td>" .$row['D_OF_BIRTH']."</td>";
	echo "<td>" .$row['PLACE_OF_BIRTH']."</td>";
	echo "<td>" .$row['PLACE_OF_DEATH']."</td>";
	echo "<td>" .$row['ERECTED_BY']."</td>";
	echo "<td>" .$row['ADD_INFO']."</td>";
	echo "</tr>";
		
	}
	echo "</table>";
	//if nothing found prints out the following.
    if(!$rows)
    echo "No results where found";
	
    }
}
//if no search terms entered prints the following.
else{
  echo "You must enter valid search terms";
}
    
    
    ?>

Thanks for the help