CSS to Javascript Menu

We have a CSS menu located on our website at [login to view URL] The problem is, currently the sub-menu is only visible when you mouseover it and it disappears when a new page loads. I want the sub-menu to remain visible whenever you are on the parent category pages, or any of the sub-category pages. I still want the menu to appear when you mouseover as well, but I want it to remain visible after you've clicked any of the menu options under that category. I've attached the PHP file that creates the Menu as well as the CSS file for styling. You can pull the rest of the files you need from the site.