I've got a problem with my app.
Ive got 3 listSelectors like this one:

        this.attributes = {
            choices: [
                {label: "1", value: "1"},
                {label: "2", value: "2"},
                {label: "3", value: "3"}
        this.model = {
            value: "1",
            disabled: false

And I have one textfield like this:

<input name="nr1" class="text_field" id="gewicht" type="text" size="5" value="0"/>

Well the problem:

The Textfield should display the result of the formula (listSelector Value a * list Selector Valie b * listSelector c) dynamicly.
That means everytime a selector changes the result should have changed relating to the formula.
How this problem could be solved?