varying behavior in an include per page

[mimages]

I'd like to have an included file for a sidebar menu that shows the current
page's selected item as grayed out, or some other effect. How can I detect
the current link in that include and cause it's related menu to display
differently? I considered having a hidden asterisk or small arrow to the
left of the item appear if it's link matches the current page.

Thanks in advance for the suggestion.

mim