/*********************************************************************************
 **  Super Efficient Rollovers by Danny Goodman                                 **
 **  Written 07/01/2003; Accessed 02/19/2008                                    **
 **  http://www.oreillynet.com/pub/a/javascript/2003/07/01/bonusrecipe.html     **
 *********************************************************************************/

function initMaps() {
   if (document.getElementById) {
      var mapIds = initMaps.arguments;    // pass string IDs of containing map elements
      var i, j, area, areas;

      for (i = 0; i < mapIds.length; i++) {
        areas = document.getElementById(mapIds[i]).getElementsByTagName("area");

        for (j = 0; j < areas.length; j++) {  // loop thru area elements
           area = areas[j];
           area.onmousedown = imgSwap;    // set event handlers
           area.onmouseout = imgSwap;
           area.onmouseover = imgSwap;
           area.onmouseup = imgSwap;
        }
      }
   }
}

// image swapping event handling
function imgSwap(evt) {
   evt = (evt) ? evt : event;                   // equalize event models
   var elem = (evt.target) ? evt.target : evt.srcElement;
   var imgClass = elem.parentNode.name;         // get map element name
   var coords = elem.coords.split(",");         // convert coords to clip
   var clipVal = "rect(" + coords[1] + "px " +
                           coords[2] + "px " +
                           coords[3] + "px " +
                           coords[0] + "px)";
   var imgStyle;
   
   switch (evt.type) {
      case "mousedown" :
         imgStyle = document.getElementById(imgClass + "Down").style;
         imgStyle.clip = clipVal;
         imgStyle.visibility = "visible";
         break;
      case "mouseout" :
         document.getElementById(imgClass + "Over").style.visibility = "hidden";
         document.getElementById(imgClass + "Down").style.visibility = "hidden";
         break;
      case "mouseover" :
         imgStyle = document.getElementById(imgClass + "Over").style;
         imgStyle.clip = clipVal;
         imgStyle.visibility = "visible";
         break
      case "mouseup" :
         document.getElementById(imgClass + "Down").style.visibility = "hidden";
         // guarantee click in IE
         if (elem.click) {
             elem.click();
         }
         break;
   }
   evt.cancelBubble = true;
   return false;
}