Weird URL CKFinder

When I am calling ckfinder from a javscript call the popup is opening with the url from the current page;

http://local.carrot3/carrot/pages/update/id/1

rather than something like;

http://local.carrot3/assets/ckfinder/ck ... pe=Content

The js code is;

function BrowseServer() {
   var finder = new CKFinder();
   finder.resourceType = 'Menus';
   finder.selectActionFunction = function(fileUrl) {
      $('input[name="menu_image"]').val(fileUrl);
      alert(fileUrl);
      var filename = fileUrl.substr(fileUrl.lastIndexOf("/") + 1);
      $('#thumb').attr('src', fileUrl);
   }
   finder.popup();
}