function newwin(url,win_width,win_height){
  winsetup = "toolbar=no,top=0,left=0,,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes";
  if(win_width > 0){
    winsetup += ",width=" + win_width;
  }else{
    winsetup += ",width=500";
  }
  if(win_height > 0){
    winsetup += ",height=" + win_height;
  }else{
    winsetup += ",height=300";
  }
  window.open(url,"",winsetup);
  return false;
}