test.js

// process received format options
function inputFormatChanged(id, value, stringValue) {
    switch (id) {
        // handle the "Bold" button
        case TXTextControl.InputFormatProperty.Bold:
            if (value == true) 
                $("#bold").prop("checked", true);
            else 
                $("#bold").prop("checked", false);             
            break;       
    }
}