no sure what you mean by "do"
but if your talking about how to access an unknown number of variables from a form
<?php
print_r($_POST['ride']);
?>
<input name="ride[]">
<input name="ride[]">
<input name="ride[]">
<input name="ride[]">
by putting [] after the name of the filed in the html, php will load the data into an array. now you can do a foreach or however you want to loop through the array.