<hlayout
    style="padding-left: 40px;padding-top:20px;padding-bottom:20px;"
    hflex="1" vflex="1">
    <separator />

    <listbox id="candidateLb" vflex="true" width="250px"
        multiple="true"   model="${arg.candidateModel}">
        <listhead>
            <listheader label="Default Column List"></listheader>

        </listhead>
        <template name="model" var="each">
            <listitem>
                <listcell label="${each}" />

            </listitem>
        </template>
    </listbox>

    <vbox spacing="10px">
        <image style="cursor:pointer" id="chooseAllBtn"
            src="/images/rightrightarrow_g.png" />
        <image style="cursor:pointer" id="chooseBtn"
            src="/images/rightarrow_g.png" />
        <image style="cursor:pointer" id="removeBtn"
            src="/images/leftarrow_g.png" />
        <image style="cursor:pointer" id="removeAllBtn"
            src="/images/leftleftarrow_g.png" />
    </vbox>
    <listbox id="chosenLb" vflex="true" width="250px"
          model="${arg.chosenDataModel}" >
        <listhead>
            <listheader label="Selected Column List"></listheader>

        </listhead>
        <template name="model" var="each">
            <listitem>

                <listcell label="${each.value}" >
                <separator orient="vertical"  />

            <b >    <checkbox checked="${each.checked}" /></b>
                </listcell>
            </listitem>
        </template>
    </listbox>

    <vbox spacing="10px">
        <image style="cursor:pointer" id="topBtn"
            src="/images/upuparrow_g.png" />
        <image style="cursor:pointer" id="upBtn"
            src="/images/uparrow_g.png" />
        <image style="cursor:pointer" id="downBtn"
            src="/images/downarrow_g.png" />
        <image style="cursor:pointer" id="bottomBtn"
            src="/images/downdownarrow_g.png" />
    </vbox>

</hlayout>

<checkbox onCheck="@command('select',param=each)" />



@Command("select")
public void myMethod(@BindingParam("param") paramType param) {
    //Do your update thing here

}