Utilities = {};

Utilities.changeMenuImage = function(obj, mode)
{
  var ext = obj.src.substr(obj.src.lastIndexOf('.')+1);
  var picname = obj.src.substr(obj.src.lastIndexOf('/')+1);

  if (ext.match('jpg')) {
    if (picname.match('_hover.jpg')) {
      picname = picname.replace('_hover.jpg', '.jpg');
    }
    else{
      picname = picname.replace('.jpg', '_hover.jpg');
    }
  }
  else{
    if (picname.match('_hover.gif')) {
      picname = picname.replace('_hover.gif', '.gif');
    }
    else{
      picname = picname.replace('.gif', '_hover.gif');
    }
  }

  obj.src = obj.src.substr(0, obj.src.lastIndexOf('/')+1) + picname;
}