function openWin(linkforopen) {
    var w=screen.width;
    var h=screen.height;
    var ww=480;
    var hh=400;
    var top=(h-hh)/2;
    var left=(w-ww)/2;
    if ((win)&&(win.closed)) {
       win=0;
    };
    if (!win) {
        win=open(linkforopen,'mywin','toolbar=0,scrollbars=1,resizable=yes,location=no,status=yes,menubar=no,toolbar=no, top='+top+', left='+left+', height='+hh+', width='+ww);
        win.focus();
    } else {
        win.focus();
    };
};

function closeWin() {
  if (win) {
      win.close();
    };
};
win=0;