AlloyUI: Add Element on object 'modal'

I try to create a Portlet which use a JSP with Alloy UI to display informations.

I like the effect of the module 'Modal' - Link

The effect is, that a box opens, if I click a button (you can see it if you follow the link).

There are two buttons in this example. I want to replace them by a text field / input field.

How can I do this?

Sincerely, JC.

Solution

For me, 'contentBox' worked fine. I added to the modal object

contentBox: '#contentBox',

and defined a div container with my textbox in

<div id="contentBox">
    <aui:form>
        <aui:fieldset>
            <aui:input name="productName" size="45" />
            <aui:button-row>
                <aui:button id="closeModal" value="Close" class="btn"></aui:button>
                <aui:button type="submit" onSubmit="cm();" />
            </aui:button-row>
        </aui:fieldset>
    </aui:form>
</div>

I don't know if there is a better solution, but I had to write the div container in the html content, but I wanted to display it only in the modal box that opens by click. So I had to hide it, it works by adding

render: '#modal',

to the modal object.