Autopopulate textarea from database based on dropdown selection - php

Question

I am trying to autopopulate a textarea with values from a (wordpress) database based on the value selected in a select menu. Basically the select menu contains a list of teams and I wish to populate my textarea with names of the players from the selected team.
The problem is that I need to convert the selected text to a php variable in order to use it to query the database. Like so:
PHP
$usergroups = $mingleforum->get_usergroups();
$team_title = $_GET['usergroup'];
$team_id = get_page_by_title( $team_title );
$players = get_users( array (
'meta_key' => 'team-meta',
'meta_value' => $team_id
));
JS
jQuery(function(jQuery){
jQuery('#usergroup').change(function() {
jQuery.ajax({
type: "GET",
url: "http://localhost:8888/dev_wordpress/wp-admin/admin.php?page=mfgroups&mingleforum_action=usergroups&do=add_user_togroup",
data: { usergroup: jQuery(this).find(':selected').text() }
}).done(function( msg ) {
alert( "Data Saved: " + msg );
});
});
});
UPDATE: corrected the url (based on #jterry 's comment) and no longer getting error (although it still isn't working)
I am getting the following error:
GET http://localhost:8888/dev_wordpress/wp-admin/wpf-addusers.php?usergroup=Coq+and+Bulldog 404 (Not Found)

Answer 1

For the points! :D
wpf-addusers.php doesn't exist at that path. Specify the absolute URI and you'll at least make it past the 404 error. Also, it looks like your url parameter has "" on both sides of the variable - you just need one on each side.
EDIT
To access the variable you're looking for (usergroup) to use in your PHP script, you can use $_GET['usergroup']. From there, you can use it as you see fit or insert it as the value of an input element.
If you use the value in an input element, be sure to use htmlentities to properly escape the value.