[jQuery] table td show/hide

function tableColShow(tableId, idx, showFlag){

       if( showFlag == true){

            $( "#" + tableId +" col:nth-child(" + idx +")").show();

            $( "#" + tableId +" th:nth-child(" + idx +")").show();

            $( "#" + tableId +" td:nth-child(" + idx +")").show();

      } else{

            $( "#" + tableId +" col:nth-child(" + idx +")").hide();

            $( "#" + tableId +" th:nth-child(" + idx +")").hide();

            $( "#" + tableId +" td:nth-child(" + idx +")").hide();

      }

}

tableColShow( "etcListTbl" , 3 , true);