sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
                @Override
                public boolean onQueryTextSubmit(String query) {

                if(query.length==0){
                  'lv.setadapter(null);'
}
                  SenderReceiver sr=new SenderReceiver(MainActivity.this,urlAddress,query,lv,noDataImg,noNetworkImg);
                    sr.execute();
                    return false;
                }
                @Override
                public boolean onQueryTextChange(String query) {
                      if(query.length==0){
                  'lv.setadapter(null);'
            }
                  SenderReceiver sr = new SenderReceiver(MainActivity.this, urlAddress, query, lv, noDataImg, noNetworkImg);
                        sr.execute();
                        return false;

                }
            });