Checkbox remains unchecked after calling Ajaxed Action

Question

I am using strtus2

<s:checkbox  name="checkAll" theme="simple" fieldValue="true" value="%{checkAll}"
  onclick="javascript:show_op_col_url();return false;"></s:checkbox>

Java Script

function show_op_col_url() {
    dojo.event.topic.publish("show_op_col_url");
}

Action Class :

        protected boolean checkAll;

        public boolean getCheckAll() {
            return checkAll;
        }
        public boolean isCheckAll() {
            return checkAll;
        }

public String showOptionalColumns() {
String retString = SUCCESS;

..... //Comes here ..... return retString; }

Strutx.xml

<action name="showINOptionalColumns"
            class="com.search.action.SearchAction"
            method="showOptionalColumns">
            <result name="success">
                /callsearch/optionalColums.jsp
            </result>
        </action>

After Calling teh Action method in Action class, checkbox should be checked, but its always UN Checked. I tried debugging but it never calles the GET method. Get method is called when i come the first time on the page, before calling the Ajaxed action.

Any help ??? please reply urgent i am caught with no soluton for this.