[ecommerce]

I would like to hide temporarily the Category Menu that is on the left side
when vistior is NOT in catalog (seeing a category, or seeing a product).

I only want the Category menu to show if visitor IS seeing a category or product. Else, is not available on the left side.

I thought about using this, but I don't know where and how to put it.

What file, and before and after what?

{if $main eq "catalog" and $current_category.category eq ""}

Thanks.