<div class="container">
  <div class="row">
    <div class="col-xs-12 col-md-offset-2">
      <form>
        <div id="user-data">
          <div class="form-group">
            <label for="username">Username</label>
            <input type="text" id="username" class="form-control">
          </div>
          <button class="btn btn-default" type="button"
          > Suggest a Username</button>
          <div class="form-group">
            <label for="email">Mail</label>
            <input type="email" id="email" class="form-control">
          </div>
        </div>
        <div class="form-group">
          <label for="city">Which city do you live</label>
          <select id="city" class="form-control">
            <option value="pune">Pune</option>
            <option value="mumbai">Mumbai</option>
          </select>
        </div>
        <button class="btn btn-primary" type="submit">Submit</button>
      </form>
    </div>
  </div>
</div>