protected boolean onTap(int index) {
   OverlayItem item = locations.get(index);
   AlertDialog.Builder builder = new AlertDialog.Builder(TaxiDirectActivity.this);
   builder.setTitle(item.getTitle());
            builder.setMessage(item.getSnippet());
            builder.setNeutralButton("새창열기", 
              new DialogInterface.OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                }
            });
            builder.setNegativeButton("취소", 
              new DialogInterface.OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                }
            });
            //builder.setPositiveButton("positive", new DialogInterface.OnClickListener() {
                //@Override
                //public void onClick(DialogInterface dialog, int which) {
                //}
            //});
            builder.show();  
            return true;