Sites.Selected | Graph API SharePoint Permission

MVC Ajax Post

$.ajax({
            url: 'http://localhost/webservice/delete_pdf.php',
            data: {delete_array: jsonString},
            dataType: 'json',
            type: 'POST',
            success: function(data){
                // Retrieve the success_delete array from json response.
                var toDelete_Array = data.success_delete;
                // Remove the filenames from the displayed list.
                //iterate through the success_delete array
               $.each(toDelete_Array,function(i, file_name){
                   // The id of each wrapper_div member is equal to corresponding filename
                   var x = $('#'+file_name).attr('id');
                   console.log('id for div: '+ x); <---- this returns 'undefined'

            // I have tried $('#'+file_name).remove(); and nothing happens. I am guessing it is due to the 'undefined' id of the div that i am trying to delete.
                });

                    },
            error: function(jqXHR, stringMessage, string){
                        alert(stringMessage);
                    }
                });
    }