Edit in JSFiddle

document.addEventListener("DOMContentLoaded", function() {
  new FancyForm({
    renderTo: 'container',
    title: 'Register',
    width: 420,
    height: 510,
    items: [{
      type: 'set',
      label: 'User Info',
      checkbox: true,
      items: [{
        type: 'string',
        label: 'Login',
        emptyText: 'Login',
        name: 'login'
      }, {
        type: 'password',
        label: 'Password',
        emptyText: 'Password',
        name: 'password'
      }]
    }, {
      type: 'set',
      label: 'Contact Information',
      items: [{
        type: 'string',
        label: 'First Name',
        emptyText: 'First Name',
        name: 'name'
      }, {
        type: 'string',
        label: 'Last Name',
        emptyText: 'Last Name',
        name: 'surname'
      }, {
        type: 'string',
        label: 'Company',
        emptyText: '',
        name: 'company'
      }, {
        type: 'string',
        label: 'Email',
        emptyText: '',
        name: 'email'
      }, {
        type: 'combo',
        label: 'State',
        emptyText: '',
        name: 'state',
        data: stateData,
        displayKey: 'state',
        valueKey: 'key'
      }, {
        type: 'date',
        label: 'Birthday',
        name: 'birthday'
      }]
    }],
    buttons: ['side', {
      text: 'Clear',
      handler: function() {
        this.clear();
      }
    }, {
      text: 'Register',
      handler: function() {
        this.get();
      }
    }]
  });
});

var stateData = [{
  index: 0,
  key: "AL",
  state: "Alabama"
}, {
  index: 1,
  key: "AK",
  state: "Alaska"
}, {
  index: 2,
  key: "AZ",
  state: "Arizona"
}, {
  index: 3,
  key: "AR",
  state: "Arkansas"
}, {
  index: 4,
  key: "CA",
  state: "California"
}, {
  index: 5,
  key: "CO",
  state: "Colorado"
}, {
  index: 6,
  key: "CT",
  state: "Connecticut"
}, {
  index: 7,
  key: "DE",
  state: "Delaware"
}, {
  index: 8,
  key: "DC",
  state: "District of Columbia"
}, {
  index: 9,
  key: "FL",
  state: "Florida"
}, {
  index: 10,
  key: "GA",
  state: "Georgia"
}, {
  index: 11,
  key: "HI",
  state: "Hawaii"
}, {
  index: 12,
  key: "ID",
  state: "Idaho"
}, {
  index: 13,
  key: "IL",
  state: "Illinois"
}, {
  index: 14,
  key: "IN",
  state: "Indiana"
}, {
  index: 15,
  key: "IA",
  state: "Iowa"
}, {
  index: 16,
  key: "KS",
  state: "Kansas"
}, {
  index: 17,
  key: "KY",
  state: "Kentucky"
}, {
  index: 18,
  key: "LA",
  state: "Louisiana"
}, {
  index: 19,
  key: "ME",
  state: "Maine"
}, {
  index: 20,
  key: "MD",
  state: "Maryland"
}, {
  index: 21,
  key: "MA",
  state: "Massachusetts"
}, {
  index: 22,
  key: "MI",
  state: "Michigan"
}, {
  index: 23,
  key: "MN",
  state: "Minnesota"
}, {
  index: 24,
  key: "MS",
  state: "Mississippi"
}, {
  index: 25,
  key: "MO",
  state: "Missouri"
}, {
  index: 26,
  key: "MT",
  state: "Montana"
}, {
  index: 27,
  key: "NE",
  state: "Nebraska"
}, {
  index: 28,
  key: "NV",
  state: "Nevada"
}, {
  index: 29,
  key: "NH",
  state: "New Hampshire"
}, {
  index: 30,
  key: "NJ",
  state: "New Jersey"
}, {
  index: 31,
  key: "NM",
  state: "New Mexico"
}, {
  index: 32,
  key: "NY",
  state: "New York"
}, {
  index: 33,
  key: "NC",
  state: "North Carolina"
}, {
  index: 34,
  key: "ND",
  state: "North Dakota"
}, {
  index: 35,
  key: "OH",
  state: "Ohio"
}, {
  index: 36,
  key: "OK",
  state: "Oklahoma"
}, {
  index: 37,
  key: "OR",
  state: "Oregon"
}, {
  index: 38,
  key: "PA",
  state: "Pennsylvania"
}, {
  index: 39,
  key: "RI",
  state: "Rhode Island"
}, {
  index: 40,
  key: "SC",
  state: "South Carolina"
}, {
  index: 41,
  key: "SD",
  state: "South Dakota"
}, {
  index: 42,
  key: "TN",
  state: "Tennessee"
}, {
  index: 43,
  key: "TX",
  state: "Texas"
}, {
  index: 44,
  key: "UT",
  state: "Utah"
}, {
  index: 45,
  key: "VT",
  state: "Vermont"
}, {
  index: 46,
  key: "VA",
  state: "Virginia"
}, {
  index: 47,
  key: "WA",
  state: "Washington"
}, {
  index: 48,
  key: "WV",
  state: "West Virginia"
}, {
  index: 49,
  key: "WI",
  state: "Wisconsin"
}, {
  index: 50,
  key: "WY",
  state: "Wyoming"
}];

<script src="https://cdn.fancygrid.com/fancy.min.js"></script>

<div id="container"></div>