Onload from URL

I’ve got a container DIV which is the parent to multiple child, all children 100% width of parent and 0px high, all absolute position top 0, left 0 on the container (parent).

Via JS I load an additional class ‘fullHeight’ which has height as 100% making one show at a time.

How can I set it up so if I come via a link with specific parameters in the URL I load a specific child?

Also in #JavaScript _↴