I need to show "add x € to the cart and you will get free shipping"

[josias]

Hello,

I have configured my prestashop 1.5.4.1 to get free shipping purchasing a determinated amount of products.

 

I want to show this to my customer once he clics in the "check out" button of the cart.

 

For example: if I've configured 100€ for free shipping and the customer have add to the cart 70€, once he have cliced in the "check out" button and he can see the summarize of the order, I want a message telling "if you add 30€ more to your cart you will get free shipping"

 

Someone have a module for doing this? adaptation?

Thank you!