Window.Open在同一个标签页打开怎么实现？

async:false,//使AJax同步
var countdownInterval;
/*确认立即充值*/
function ToRecharge(){
var paramData = new Object();
paramData.PayType = 1;//支付宝支付
paramData.OrderMoney = parseFloat($("#spShouldPay").text());//支付总金额
var gprsTel = [];
var orderDetail = new Array();
for(var i = 0; i < deviceList.length; i++){
orderDetail[i] = new Object();
orderDetail[i].DeviceSN = deviceList[i].DeviceSN;//设备SN码
orderDetail[i].GPRSTel = deviceList[i].GPRSTel;//GPRS手机号码
orderDetail[i].PayYear = parseInt($("#hdnYear").val());//年数
orderDetail[i].PayPotency = 100;//暂时默认是两百元

gprsTel.push(deviceList[i].GPRSTel);
}
paramData.GPRSTel = gprsTel.join(",");
paramData.OrderDetail = $.toJSON(orderDetail);
paramData.rand = Math.random();
paramData.PostType = "AddRecharge";

$.ajax({
url: '/App_Ajax/Service.ashx',
data: paramData,
type: 'post',
async:false,//使AJax同步
success: function(resultData){
var jsonResult = $.parseJSON(resultData);
if(!jsonResult.success){
window.$.messager.alert('提示', "充值记录保存失败！");
newwindow.close();
return;
}

$("#backupdate").text("返回修改");
$("#timerecharge").hide();
$("#onrecharge").show();
$("#rechargesuccess").hide();
$("#hdnOrderStatus").val(jsonResult.obj.OrderStatus);
$("#hdnOID").val(jsonResult.obj.OID);

//启动一个轮询，不断去读取Recharge_Order表的OrderStatus如果成功那么就停止
CheckOrderStatus(jsonResult.obj.OID);
//window.open("http://www.baidu.com");
openPostWindow(String.format("http://{0}/Default/Service/Recharge.aspx", location.host), $.toJSON(jsonResult.obj), "_blank")
}
});
}
/*POST 打开新窗口*/
function openPostWindow(url, data, target) {
var tempForm = document.createElement("form");
tempForm.id = "tempForm1";
tempForm.method = "post";
tempForm.action = url;
tempForm.target = target;

var hideInput = document.createElement("input");
hideInput.type="hidden";
hideInput.name= "PostName"
hideInput.value= data;
tempForm.appendChild(hideInput);
document.body.appendChild(tempForm);

tempForm.submit();
document.body.removeChild(tempForm);
}