You can open window with params. Define them clearly as part of url:
Write them without single-quotes and as expected (define them separate before making part of url):
window.open("http://yourdomain.com//AllOrders/OrderDetails?billno="+billno ,"_self");
In case the value needs to be evaluated/customized:
mybillno = BillNo+"somemodification";
myurl = "http://yourdomain.com//AllOrders/OrderDetails?billno=" + mybillno;
window.open(myurl ,"_self");
Reference:
Window: open() method - Web APIs | MDN[
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Window open() Method[
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