Kendo ui 如何使用tabGroup.find（）从剑道tabstrip获取索引？

这就是我正在努力实现的目标

var tabIndex = 4; //hard coded NOT WHAT I WANT
var tabStrip = $("#navigationTab").data("kendoTabStrip");            
var item = tabStrip.tabGroup.find(':contains("Billing")');
tabIndex = item.??
 setTabUrl("navigationTab", tabIndex, '@Url.Action(Mvc.Areas.Account.Billing.ActionNames.AccountBilling, Mvc.Areas.Account.Billing.Name, new { id = Model.AccountId })');

谢谢

var tabStrip = $("#navigationTab").data("kendoTabStrip");            
var item = tabStrip.tabGroup.find(':contains("Billing")');
var tabIndex = item.index(); // tabIndex == 4