function openpopup(url,name,w,h,s,r) {
  checkout = window.open(url,'checkout','fullscreen=no,toolbar=no,status=no,menubar=no,scrollbars='+s+',resizable='+r+',directories=no,location=no,width='+w+',height='+h+',left=((screen.width/2)-('+w+'/2),top=((screen.height/2)-('+h+'/2)');
}