jQuery change event issue after show()
===

I have html document with button 'Add new' and hidden div (style='display: none;') with additional fields. When user click on button 'Add new' div become visible:

    <script>
    $(document).ready(function () {
        $('#add_new').click(function () {
                $('#add_new_panel').show();
                $(this).hide();
            });
        
        $('#selected_file').change(function(){
                alert(44);
        	});
    });
    </script>

    <div id="add_new_panel" style="display: none;">
    	<input type="file" id="selected_file" name="testFile" />
    </div>

The problem is when I choose file in input field jQuery change event on this field never fires. If I remove style='display: none;' from add_new_panel div it works correctly. But I need hide this div until user doesnt click on button. How can I do this? Maybe I can bind change event handler with another code?

P.S. On the other page this works perfectly with 'display: none;'.

Sorry for my bad english. Thanks.