Create new button for Swipe Gallery Plugin

Hi,

I try to create a new button that will open the current photo in the gallery as new window by using the function "popup('image', 'url...');

I need the current photo to be zoomable in this gallery. So I created the zoom button in gallery container:

<layer name="zoom_image" align="rightbottom" x="10" y="10" keep="true" zorder="2" url="plugins/img/zoom.png" />

But I have no idea how to assign this function 'popup' to this new button independently for each photo.

For example I have gallery:

<gallery name="gallery_X" title="X">
	<img name="img1" url="%CURRENTXML%/photos/X.jpg" title="X" />
	<img name="img2" url="%CURRENTXML%/photos/Y.jpg" title="Y" />
</gallery>

I'd like to use this new button to open windows ('popup' function) using the url provided for this photo in <img> row:
<img name="img1" url="%CURRENTXML%/photos/X.jpg" title="X" />.

I was wondering how to use 'onclick' function for <img> section in that way to let the new button to apply 'popup' function using the same url as in <img> row.

I hope that I presented the problem quite legibly.

PS. Zoom is activated for popup function in vtourskin.xml so it works for single image.

Thank you for any support.