show the child images after clicking

Hello,
As you know in the hikashop's product page we can set several images for an item. In this case the first added image will be considered as the main image for that product and the others will be shown as thumbnails (child images at class hikashop_child_image).

The problem is that these thumbnails will be shown with their real size after mouse hovering. But I need to show these images after each one is clicked. Is there any configuration to show the images after clicking and not hovering?
If not, how can I customize the code to show these images in real size after each one is clicked?

Thank You