Re: how to combine the results of two variables to echo another variable?

Or simply use arrays instead (preferred by most):

<form method="POST">
<input type=text name="field[]">
<input type=text name="field[]">
<input type=text name="field[foo]">
<input type=submit>
</form>

foreach ($_POST['field'] as $key => $value) {
...
}

http://php.net/manual/en/faq.html.php#faq.html.arrays

.