struts2 with Jquery javascript issue

Hi ,

I have my jsp as bellow

<%@ taglib prefix="s" uri="/struts-tags"%>   
<%@ taglib prefix="sj" uri="/struts-jquery-tags"%>   
<%@ taglib prefix="sjg" uri="/struts-jquery-grid-tags"%>   
<html>   
    <head>   
        <sj:head jqueryui="true" jquerytheme="redmond" />   
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">   
        <title>JQuery Grid Page</title>   
    </head>   
    <body>   
        <h1>Hello World!</h1>   
        <h2><s:property value="message"/></h2>   
        <s:url id="remoteurl" action="doHelloStruts2p3"/>   
        <sjg:grid   
            id="gridtable"  
            caption="Host Examples"  
            dataType="json"  
            href="%{remoteurl}"  
            pager="true"  
            gridModel="gridModel"  
            rowList="10,15,20"  
            rowNum="15"  
            rownumbers="true"  
            navigator="true"  
            navigatorSearch="true"  
            navigatorSearchOptions="{multipleSearch:true}"  
            >   
            <sjg:gridColumn name="hostid" index="hostid" editable="true" title="ID" formatter="integer" sortable="false"/>   
            <sjg:gridColumn name="hostname" index="hostname" editable="true" title="Name" sortable="true"/>   
            <sjg:gridColumn name="email" index="email" title="Email" editable="false" sortable="true"/>   
            <sjg:gridColumn name="remarks" index="remarks" title="Remarks" sortable="false"/>   
        </sjg:grid>   
    </body>   
</html>

So with the javascript I want make some columns editable="false" and editable="true" based on some condition.

Can some show me how to write the javascript for this.

Thank in advance.