jQuery method to dynamically display and hide a column in datagrid_jquery

$(function(){
$('#tt' ).datagrid({
title:'Report Statistics',
width:1020,
height:400,
url:'',
fitColumns:true,
loadMsg:' Retrieving, please wait...',
singleSelect:true,
nowrap:false,
columns:[[
{field:'REGION_NAME',title:'Branch',width :30,align:'center'},
{field:'COUNTY_NAME',title:'District and County',width:80,align:'center',editor:'text'},
{field: 'AREA_NAME',title:'grid',width:80,align:'center',editor:'text'},
{field:'ORG_NAME',title:'site',width:80,align: 'center'},
{field:'TOTAL_NUM',title:'Total business volume',width:40,align:'center'},
{field:'DH_NUM',title:'Single-width business Amount',width:40,align:'center'},
{field:'RH_NUM',title:'Integrated business volume',width:40,align:'center'},
{field:' YYT_NUM',title:'Business hall business volume',width:40,align:'center'},
{field:'QT_NUM',title:'Other business volume',width:40,align:'center' }
]],
toolbar:[
],
onDblClickRow: function() {
//selected = $('#tt').datagrid('getSelected');
//var index = $('#tt').datagrid('getRowIndex', selected);
//$('#tt').datagrid('beginEdit', index);
/ /progress();
//taskPreempte(selected.taskId);
}
});

$('#my_toolbar').appendTo('.datagrid-toolbar') ;

var dd = new Date();
var d1 = dd.getFullYear() "-" (dd.getMonth() 1) "-1" ;
var d2 = dd. getFullYear() "-" (dd.getMonth() 1) "-" dd.getDate() ;
$('#qryStartDate').datebox('setValue', d1); // set datebox value
$('#qryEndDate').datebox('setValue', d2); // set datebox value
refreshRpt2();

});

function refreshRpt2(){
var strStatCond = "b.region_name";
if($('#qryCon').attr("value")!=100){
param.sts = $('#qryCon') .attr("value");
alert(param.sts);
}
param.qryBeginTime =$('#qryStartDate').datebox('getValue');
//alert (param.qryBeginTime);
param.qryEndTime = $('#qryEndDate').datebox('getValue');
//alert(param.qryEndTime);

if($( '#region')!= null && $('#region').attr("checked") == true){

}
if($('#county')!= null && $('#county').attr("checked") == true){
strStatCond = ",c.county_name";
$('#tt').datagrid('showColumn', ' COUNTY_NAME');

}else{
$('#tt').datagrid('hideColumn', 'COUNTY_NAME');
}

if($(' #area')!= null && $('#area').attr("checked") == true){
strStatCond = ",d.area_name";
$('#tt'). datagrid('showColumn', 'AREA_NAME');
}else{
$('#tt').datagrid('hideColumn', 'AREA_NAME');
}
if($( '#org')!= null && $('#org').attr("checked") == true){
strStatCond = ",e.org_name";
$('#tt') .datagrid('showColumn', 'ORG_NAME');
}else{
$('#tt').datagrid('hideColumn', 'ORG_NAME');
}
alert(strStatCond );
param.statCond = strStatCond;
param.rptName = "statBusiRpt";
JSBaseCall.execute(param,showResult2);
}
//Display record set
function showResult2(data){
var strJson=data["defaultJsonString"];
var result=eval('(' strJson ')');
//alert(strJson);
if ( result.KEY_JSCALL_RESULT){
if (result.KEY_SERVICE_RES){//Success
totalRec=result.KEY_TOTAL_REC;
var d={"total":pageShowRec,
"rows":result.defaultAList
};
$('#tt').datagrid('loadData',d);
}
}
}