if(document.getElementById) {
       var getRefById = function(id) {
         return document.getElementById(id);
       };
     } else if(document.all) {
       var getRefById = function(id) {
         return document.all[id];
       };
     } else {
       var getRefById = function() {
         return null;
       };
     }

     var activeAnchor = null, oldStyle;

     function changeStyle(href) {

       var d, i;

       if(-1 == (i = href.indexOf('#'))) {return;}
       d = getRefById(href.substring(i + 1));

       if(d && activeAnchor != d) {
         if(activeAnchor) {
           activeAnchor.className = oldStyle;
         }
         if(d) {
           oldStyle = d.className;
           d.className += ' mapSelect';
           activeAnchor = d;
         }
       }
     }