Can I have in a PHP page link to different pages plus ‘remember’ what the user answered in this page?

if ($Topic == 'TopicA')

{
echo
"My age is:
<select name=\"Age_Group\">
<option>Select Age Group</option>
<option>0 - 20</option>
<option>21 - 25</option>
<option>26 - 30</option>
<option>31 - 35</option>
<option>36 - 40</option>
<option>41 - 99</option>
</select>";
echo

// How do I send him to URL1 AND 'remember' what the user filled here at the AGE Group variable

}

elseif ($Topic == 'TopicB')

{
echo
"My age is:
<select name=\"Age_Group\">
<option>Select Age Group</option>
<option>0 - 20</option>
<option>21 - 25</option>
<option>26 - 30</option>
<option>31 - 35</option>
<option>36 - 40</option>
<option>41 - 99</option>
</select>";
echo

// How do I send him to URL1 AND 'remember' what the user filled here at the AGE Group variable

}

echo " ";
?>

use cookies, and redirect, which can be looked up using the PHP Manual, looking under the header() and setcookie() section no better way to learn than using the manual