For循环内部For循环Javascript

for (var i = 0, len=data.ORDER_STATUS[0].ORDERS.length; i < len; i++) {
     if (data.ORDER_STATUS[0].ORDERS[i].SEC_TYPE=="MLEG") {
           for (var i = 0; i < data.ORDER_STATUS[0].ORDERS[i].LEGS.length; i++) {
                 LEGS +='<tr class="MLEGS"><td class="orderFirst">' +
                 data.ORDER_STATUS[0].ORDERS[i].LEGS[i].SYMBOL +
                 '</td><td>' + data.ORDER_STATUS[0].ORDERS[i].LEGS[i].ACTION +
                 '</td><td>' + data.ORDER_STATUS[0].ORDERS[i].LEGS[i].QTY +
                 '</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr>';
           }
     }
}
for (var i = 0, len=data.ORDER_STATUS[0].ORDERS