Image or checkbox instead of the text "In stock" on product page

[octavc]

I must create a template for a customer and on the design they sent me, the designer had the "magnific" idea to replace the text "In stock" on product page with a checkbox.

 

So in theory when the product is available to order the customer will see a checked checkbox (an image representing this")

When the product is not available to order the customer will see then an unchecked checkbox (also an image)

 

I looked into product.tpl but on I just can't see which is the variable holding this.

 

Using the image url when editing product in admin will just display the url.

Inserting the html code <img src ="checkedimage"> will tell forbiden characters.

 

I'm running out of ideas.