var pages = new Array(['book','About the Book','1'],
              ['author','About the Author','1'],
              ['excerpt','Read an Excerpt','1'],
              ['review','Reviews','1'],
              ['units','Units of Interest','1'],
              ['maps','Maps & Graphics','1']);
function boldLinks() {
    var docHref = document.location.href;
    var pageId = docHref.substring(docHref.lastIndexOf('/')+1, docHref.lastIndexOf('.'));
    for (var i=0;i<pages.length;i++) {
        if (pageId == pages[i][0]) {
            document.getElementById(pages[i][0]).innerHTML = '<b>' + pages[i][1] + '</b>';
        } else {
            document.getElementById(pages[i][0]).innerHTML = '<b><a href="' + pages[i][0] + '.html">' + pages[i][1] + '</a></b>';
        }
    }
}