[ContentType(GUID = "a7d7f7ce-8f04-49cc-83d9-d37466ca0be9")]
    public class CityElementBlock : TextboxElementBlock
    {

    }

[ContentType(GUID = "aebffdd1-82f4-4119-a297-f2fe2b7010a4")]
    public class ZipCodeElementBlock : TextboxElementBlock
    {

    }




@using EPiServer.Forms.Helpers.Internal
@model ZipCodeElementBlock

@{
    var formElement = Model.FormElement;
    var labelText = Model.Label;
}

@using (Html.BeginElement(Model, new { @class = "FormTextbox" + Model.GetValidationCssClasses(), data_f_type = "textbox" }))
{
    <label for="@formElement.Guid" class="Form__Element__Caption">@labelText</label>
    <input name="@formElement.ElementName" id="@formElement.Guid" type="text" class="FormTextbox__Input" placeholder="@Model.PlaceHolder" value="@Model.GetDefaultValue()" @Html.Raw(Model.AttributesString) data-f-datainput data-postal-search/>

    @Html.ValidationMessageFor(Model)
    @Model.RenderDataList()
}

<script>
    $(document).ready(function() {
        var input = $('[data-postal-search]'),
            result = $('[data-postal-search-result]');

        result.attr("readonly", "readonly");

        input.on('keyup', $.throttle(350, function () {
            var element = $(this),
                value = element.val(),
                url = "http://adressesok.posten.no/api/v1/postal_codes.json?postal_code=" + value + "&callback=";

            if (value.length === 4) {
                $.ajax({
                    method: 'GET',
                    url: url
                }).done(function (data) {
                    result.val(data.postal_codes[0].city);
                });
            }

        }));
    });
</script>

@using EPiServer.Forms.Helpers.Internal
@model CityElementBlock

@{
    var formElement = Model.FormElement;
    var labelText = Model.Label;
}

@using (Html.BeginElement(Model, new { @class = "FormTextbox" + Model.GetValidationCssClasses(), data_f_type = "textbox" }))
{
    <label for="@formElement.Guid" class="Form__Element__Caption">@labelText</label>
    <input name="@formElement.ElementName" id="@formElement.Guid" type="text" class="FormTextbox__Input" placeholder="@Model.PlaceHolder" value="@Model.GetDefaultValue()" @Html.Raw(Model.AttributesString) data-f-datainput data-postal-search-result/>

    @Html.ValidationMessageFor(Model)
    @Model.RenderDataList()
}


Legg så begge blokker i skjemaet du vil ha denne funksjonen i