function link (link){
        window.location = link;
}

function back (){
   window.opener.location = window.opener.location;
   window.close();
}

 function window_open (url, w, h){
    a = window.open (url, "mywindow","location=0,status=0,scrollbars=1, width=" + w + ",height=" + h);
  }


//back function