Use fileupload script in a modal/dialog box

Question

I'd like to use my file-upload script in a modal/dialog which is created after the document is loaded.

Also i use the alertify library to have a better dialog box.

Here is my code :

1 - My alertify script (profile.js) which create the form :

 $("#profil").click(function () {
    alertify.minimalDialog || alertify.dialog('minimalDialog', function () {
        return {
            main: function (content) {
                this.setContent(content);
                this.set('resizable',true).resizeTo('80%','50%');
                this.set('title',"Changer votre photo de profil");
            }
        };
    });
    alertify.minimalDialog('<form id="formupload" method="POST"><p><img id="imagepreview" class="id_img" width="auto" height="60px" src="../../images/profils/min/3266.jpg"></p> <p class="label-w100"><input id="fileupload" type="file" name="files[]" accept="image/gif, image/jpg, image/jpeg, image/png"/><div id="progress"><div class="bar" style="width: 0%;"></div></div></p><p id="chargementimage"></p><div class="grand-trait"></div><p class="center"><input id="submit" type="submit" value="Envoyer" class="envoyer"/></p></form>');
})

2 - My script which would allow to load the image in a temporary folder

$(document).on("change", "#fileupload",  function(){
    var url = window.location.hostname + "/json/ec-informations/upload_img2.php";
    alert(url);
    $('#fileupload').fileupload({
        dataType: 'json',
        url: url,
        maxChunkSize: 1000000,
        maxFileSize: 5000000,
        formData: {'csrf': 'csrf'},

        done: function (e, data) {
            fichier = "";
            $.each(data.result.files, function (index, file) {
                $('#progress').after(file.name).appendTo(document.body);
                fichier = file.name;
                $("input[name=img_tmp]").val(fichier);
                $('#progress').appendTo('#chargementimage');
                $('#chargementimage').after('Image correctement chargée, finalisez votre proposition en appuyant sur Envoyer.');
                $('#imagepreview').attr('src', '' + fichier);
                if (file.error) {
                    alert(file.error);
                    location.reload();
                }
            });
            if (data.erreur == 'Filetype not allowed') {
                alert('Le format de fichier est mauvais');
            }
        },
        progressall: function (e, data) {
            var progress = parseInt(data.loaded / data.total * 100, 10);
            $('#progress .bar').css(
                'width',
                progress + '%'
            );
        }
    });

});

My problem is that when I select the image, i dont succeed to bring informations inside my upload_img2.php.

Usually, i have no problem with uploadfile because my form is created before, but not here.

I hope i've been clear, thanks you for your help !