function open_new(url)
  {
    if (window.screen)
    {
      var w = screen.width;
      var h = screen.height;
      var center_x = w / 2;
      var center_y = h / 2;
      var new_width;
      var new_height;
      var new_left;
      var new_top;

      if(w <= 800)
      {
        new_width  = 400;
        new_height = 400;
        new_left   = center_x - (new_width / 2);
        new_top    = center_y - (new_height / 2);
      }

      if(w > 800)
      {
        new_width  = 700;
        new_height = 500;
        new_left   = center_x - (new_width / 2);
        new_top    = center_y - (new_height / 2);
      }

      var new_Window = window.open(url, "", "menubar=no, location=no, status=no, toolbar=no, scrollbars=auto, resizable=no , width=" + new_width + ", height=" + new_height + ", top=" + new_top + ", left=" + new_left + "");
      new_Window.focus();
    }
  }

function open_locatie(url)
  {
    if (window.screen)
    {
      var w = screen.width;
      var h = screen.height;
      var center_x = w / 2;
      var center_y = h / 2;
      var new_width;
      var new_height;
      var new_left;
      var new_top;

      new_width  = 610;
      new_height = 560;
      new_left   = center_x - (new_width / 2);
      new_top    = center_y - (new_height / 2);

      var new_Window = window.open(url, "", "menubar=no, location=no, status=no, toolbar=no, scrollbars=auto, resizable=no , width=" + new_width + ", height=" + new_height + ", top=" + new_top + ", left=" + new_left + "");
      new_Window.focus();
    }
  }


var message="";
function clickIE() {if (document.all) {(message);return false;}}
function clickNS(e) {if
(document.layers||(document.getElementById&&!document.all)) {
if (e.which==2||e.which==3) {(message);return false;}}}
if (document.layers)
{document.captureEvents(Event.MOUSEDOWN);document.onmousedown=clickNS;}
else{document.onmouseup=clickNS;document.oncontextmenu=clickIE;}
document.oncontextmenu=new Function("return false")