Opencart - MultiStore - Products Problem

Hello
My multi-store is working fine. The only small problem that I have it's my products. When I click "insert product" and go to Links tab, i have the choice to choose which stores I want my product to be add.
The default choice is only the default store. I need a javascript or a "trick" so when i click on the "insert product" all the stores to be choose.

I attach you an image so to understand.