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I have a problem with site based on php and tpl files, I'm a beginner with php but I think the problem is due to something like javascript or ajax. I added an addon (then it should already work perfectly) consists of two files tpl, a php file (for the user) and 2 php files (for the admin side). In admin side I have a settings page with different forms to complete: when I click on Save (type = "submit") the information entered in the form should be added to the database, but instead appears the loading image and continues indefinitely. I have no idea what it might depend on what is due or the problem, or if it depends on the php file or tpl files.

I thought that the problem could depend on this piece of code(I also removed verifyajax() but the problem remained):

if ($input->p['do'] == 'save_settings') {
verifyajax( );
$ht_statistics = $input->pc['ht_statistics'];
$ht_showlastwinners = $input->pc['ht_showlastwinners'];
$ht_lastwinners = $input->pc['ht_lastwinners'];

$ht_profit = $input->pc['ht_profit'];

$ht_win = $input->pc['ht_win'];

$ht_cost = $input->pc['ht_cost'];


if (!is_numeric( $ht_lastwinners )) {
    serveranswer( 0, 'Error: Insert number' );
}


if (!is_numeric( $ht_profit )) {
    serveranswer( 0, 'Error: Insert number' );
}


if (!is_numeric( $ht_win )) {
    serveranswer( 0, 'Error: Insert number' );
}

$upd = $db->query('UPDATE settings SET value=\'' . $ht_statistics . '\' WHERE field=\'ht_statistics\'' );
$upd = $db->query('UPDATE settings SET value=\'' . $ht_showlastwinners . '\' WHERE field=\'ht_showlastwinners\'' );
$upd = $db->query('UPDATE settings SET value=\'' . $ht_lastwinners . '\' WHERE field=\'ht_lastwinners\'' );
$upd = $db->query('UPDATE settings SET value=\'' . $ht_profit . '\' WHERE field=\'ht_profit\'' );
$db->query('UPDATE settings SET value=\'' . $ht_cost . '\' WHERE field=\'ht_cost\'' );
$upd = $db->query('UPDATE settings SET value=\'' . $ht_win . '\' WHERE field=\'ht_win\'' );
serveranswer( 1, 'Settings were updated' );

thanks to the help that you give me, and I apologize if the problem is trivial to you but for me as a beginner it is hard to find, if you need I add all the files that make up the addon.

EDIT

I tried to print the query by entering print_r but I could not find anything, maybe something wrong.

I used the browser console that gave me these answers: mozilla:

expected 'none' or url but found 'alpha('. error in parsing value for 'filter'. declaration dropped

chrome:

POST http://www.example.com/admin/modules/head_tail.php 404 (Not Found)
                                                jquery.min.js:2 
send                                             jquery.min.js:2
p.extend.ajax                                     jquery.min.js:2
p.(anonymous function)           ?view=addon_modules&module=head_tail:83
addonfrm                         ?view=addon_modules&module=head_tail:126
onsubmit

seeing the chrome error console I think the problem is in another php file and it is due to this code fragment in javascript:

<script type="text/javascript">
function addonfrm(id){
    $(\'#\'+id).l2block();
    httplocal = \'/admin/modules/head_tail.php\';
    var jqxhr = $.post(httplocal,$("#"+id).serialize(), function(data) {
        if(data.status == 0){
            $("#"+id).l2error(data.msg);
            $("#"+id).l2unblock();
        }else if(data.status == 1){
            $("#"+id).l2success(data.msg);
            $("#"+id).l2unblock();
        }
   }, "json");
    return false;
}
</script>

the problem may be due to the .js files? I installed several add-on, and all of them have this problem.