Valums file-uploader: Limit user downloads on credit

Im using Valums awesome file uploader - https://github.com/valums/file-uploader

One thing I want to add to it is a restriction based on the balance of the user account.

The first image is always free, so you can upload one image, even if your balance is 0.

Additional images will require 0.50 or credit. If they do not have enough credits, he will show a warning and the file will not be uploaded.

balance can be obtained from php session variable $_SESSION['user']['credit']

Here is the code so far

function createUploader(){ 
    var running = 0;    
    var uploader = new qq.FileUploader({
        multiple: true,
        element: $('#file-uploader')[0],
        action: 'classes/upload.item.php',
        allowedExtensions: ['jpg', 'png', 'gif'],
        params: {item: '<?php echo $item_id ?>'},
        onSubmit: function(id, fileName){
            running++;
            $('.button').replaceWith('<a class="button large grey full-width">Please wait...</a>');
        },
        onComplete: function(id, fileName, responseJSON){
            running--;
            $(".thumbnails").append('<li class="span2"> <a class="thumbnail"><img src="<?php echo $path; ?>'+fileName+'" /></a> </li>');
            if(running==0){
              $('.button').replaceWith('<a class="button large green full-width" href="confirm/<?php echo $item_id; ?>">Continue to next step</a>');                                 
            }           

        },
        onCancel: function(id, fileName){
            running--;
        },
        debug: true
    });           
}

Sorry, the question is, can you offer any recommendations on the implementation of what I described above?

Greetings

Edit: , (, ).

return false , , , , , .

onSubmit (String id, String fileName) - , . , , . false .

<?php
// count uploaded files
$path = 'uploads/' . $_SESSION['user']['username'] . '/' . $item_id . '/thumbs/s_';
$files = glob($path . '*.*'); 


// has free upload been used yet? incase of page refresh etc
if (count($files) >= 1) {
    $used_free = 'true';
} else {
    $used_free = 'false';
}
?>

<script>
    function createUploader(){ 
        var credit = <?php echo $_SESSION['user']['credit'] ?>;  
        var used_free = <?php echo $used_free ?>; 
        var running = 0; 


            var uploader = new qq.FileUploader({
                multiple: true,
                element: $('#file-uploader')[0],
                action: 'classes/upload.item.php',
                allowedExtensions: ['jpg', 'png', 'gif'],
                params: {item: '<?php echo $item_id ?>'},
                onSubmit: function(id, fileName){   
                    console.log(used_free);
                    if (!used_free) {
                        used_free = 'true';
                        running++;
                        $('.button').replaceWith('<a class="button large grey full-width">Please wait...</a>');
                    } else {
                        $.get('ajax/getCredit.php', function (data) {
                            if (data.credit >= 0.5) {
                                running++;
                                $('.button').replaceWith('<a class="button large grey full-width">Please wait...</a>');
                            } else {
                                alert('you do not have enough credits');
                                return false;
                            }
                        }, "json");
                    }
                },
                onComplete: function(id, fileName, responseJSON){
                    running--;
                    $(".thumbnails").append('<li class="span2"> <a class="thumbnail"><img src="<?php echo $path; ?>'+fileName+'" /></a> </li>');
                    if(running==0){
                      $('.button').replaceWith('<a class="button large green full-width" href="confirm/<?php echo $item_id; ?>">Continue to next step</a>');                                 
                    }           
                },
                onCancel: function(id, fileName){
                    running--;
                },
                debug: true
            });      
    }
</script> 

,

function createUploader(){ 
    var credit = <?php echo $_SESSION['user']['credit'] ?>;  
    var used_free = <?php echo $used_free ?>; 
    var running = 0; 


    var uploader = new qq.FileUploader({
        multiple: true,
        element: $('#file-uploader')[0],
        action: 'classes/upload.item.php',
        allowedExtensions: ['jpg', 'png', 'gif'],
        params: {item: '<?php echo $item_id ?>'},
        onSubmit: function(id, fileName){   
            if (!used_free) {
                used_free = 'true';
                running++;
                $('.button').replaceWith('<a class="button large grey full-width">Please wait...</a>');
            } else {
                if (credit >= 0.5) {
                    running++;
                    credit = credit - 0.5;
                    $('.button').replaceWith('<a class="button large grey full-width">Please wait...</a>');
                } else {
                    alert('you do not have enough credits');
                    return false;
                }
            }
        },
        onComplete: function(id, fileName, responseJSON){
            running--;
            $(".thumbnails").append('<li class="span2"> <a class="thumbnail"><img src="<?php echo $path; ?>'+fileName+'" /></a> </li>');
            if(running==0){
              $('.button').replaceWith('<a class="button large green full-width" href="confirm/<?php echo $item_id; ?>">Continue to next step</a>');                                 
            }           
        },
        onCancel: function(id, fileName){
            running--;
        },
        debug: true
    });      
}

,