ImageMenu sub-items are not available to access from jscript

My site has different products. I have created menu using imagemenu. I want to highlight a menu item that is related with a product, when I am on the product view page. But as menu-sub item is not available for manipulation on page view, I am not able to do that.

I observed that imagemenu generates sub-menu items on callback of main menu item.
Hence sub-menu items are not available to change image using jscript.

If anyone has faced the same issue and resolved it, please reply.