Using "lightbox browsing" with singlepic

I want to insert pictures from a nextgen gallery in my blog entry, but I want to insert the images one by one in my text. Something like this:

bla bla bla
photo 1
bla bla bla
photo 2
bla bla bla
photo 3

I then want to have a lightbox effect to see a larger version of the photos. I’m able to achieve this using the singlepic shortcode. But I would like to do one more thing: when I’m looking at the larger version I want to be able to move between the images without having the close/open the lightbox for each photo.

This is how my code looks like

bla bla bla
[singlepic id=12 w=640 float=center]
bla bla bla
[singlepic id=13 w=640 float=center]
bla bla bla
[singlepic id=14 w=640 float=center]

But the result is that I need to click to show one picture, then close it and then open next. This is probably due to that the resulting html code:

<a href="http://example.com/x1.jpg" title="" class="thickbox" rel="singlepic13">
	<img class="ngg-singlepic ngg-center" src="http://example.com/small_x1.jpg" alt="bla" title="bla">
</a>

The other images have the rel-tag singlepic14 and singlepic12. I assume that these need to be the same value to get the effect I want but how do I do this?

I tried

[singlepic id=12 w=640 float=center rel=xh]

but it doesn’t work and I can’t find any example of how to do this.

http://wordpress.org/plugins/nextgen-gallery/