<window apply="org.zkoss.bind.BindComposer"

        viewModel="@id('vm') @init('pkg$.RadiogroupSelectedVM')" border="none"> 

        <vbox>

            <radiogroup id="radiogroup" selectedItem="@bind(vm.selected)">

                <radio id="radioa" label="Has" value="true"/>

                <radio id="radiob" label="HasNot" value="false"/>

            </radiogroup>

            ==================================

                  <label value="@bind(vm.selected)"/>

        </vbox>

    </window>

</zk>