$(document).ready(function(){
  var url = undefined;
  $("#dialog").dialog({
    autoOpen: false,
    modal: true,
    resizable: false,
    draggable: false,
    width: 500,
    buttons: {
      'Continue to PayPal': function () {
        $('#dialog').dialog('close');
        location.href = url;
      },
      Cancel: function () {
        $('#dialog').dialog('close');
      }
    }
  });
  $.each($('a.purchase-link'), function () {
    var a = $(this);
    $.data(a, 'purchase-url', a.attr('href'));
    a.attr('href', 'javascript:;');
    a.click(function() {
      url = $.data(a, 'purchase-url');
      $('#dialog').dialog('open');
      $('.ui-widget-header').css('display', 'none');
    });
  });
});