Creating clickable images of products in web

Question

I want to create clickable images of products on my webpage such that when a user clicks on a product and checks out,the quantity automatically reduces by one after which when it reaches 0 then it will display product as out of stock or a "select" button below the image which does the same function as above on checkout

Answer 1

basically

<button onclick =" doSomething()" ><img/></button>

- design a js or php function to change the quantity that is available