AddThis

how to pass url variable to addthis:url?

My site consists of a constantly changing set of flash galleries which are put together using an application that provides an API interface to provide the URL of the currently viewed image in the flash gallery.

I am trying to put the AddThis buttons on each gallery page, but am having trouble finding the right syntax to pass the URL to the buttons.

My third party app provides the image path as follows:

...
$imagepath = 'http://www.mysitename.com' + pathtemp + imageInfo.imageURL;
displayOutput("image path is: " + $imagepath);

(For debug purposes I am displaying the value of $imagepath on my page, and it is correct.)

I am using the following to set the URL for the addthis_toolbox, which isn't working:

<div id="container" class="addthis_toolbox addthis_floating_style addthis_32x32_style" addthis:url='+$imagepath+' style="left:50px;top:50px;">


What syntax do I need to be using?

Many thanks in advance for your help.