JQuery :: Cannot Find Image Within DIV

I'm working on a script for a selection of a specific item. When I select a item the image should change, so far so good. But when I select an other item, the image of the item I selected before should change back and there is where I find myself stuck. This is my script so far
var small_src = $(this).attr('src');
var new_small_src = small_src.substring(small_src.lastIndexOf('/'), small_src.lastIndexOf('.'));
$(this).attr('src', 'img' + new_small_src + '_selected.' + /[^.]+$/.exec(small_src));
This results in changing the image to a selected image, but I can't change it back when I select an other.