function printversie(url) {
  var options = "width=750, height=500";
  options += ", resizable=no";
  options += ", scrollbars=yes";
  options += ", toolbar=no";
  options += ", location=no";
  options += ", directories=no";
  options += ", status=no";
  options += ", menubar=no";
  options += ", copyhistory=no";

  var px_from_top   = 25;
  var px_from_left  = (screen.availWidth - 750)/2;
  options += ", top=" +px_from_top;
  options += ", left=" +px_from_left;

  // printwin = window.open(url, '_blank', options);
  printwin = window.open(url, 'Printversie', options);
  // return CheckOpen();
  return false;
  }

function CheckOpen () {
  if (printwin.closed == true) {
    // alert("Het venster is gesloten!");
    return true;
    }
  else {
    // alert("Het venster is open!");
    return false;
    }
  }

function position_this() {
  // var this_x = (screen.availWidth - 750)/2;
  // var this_y = 25;
  // window.moveTo(this_x,this_y);
  }