please tell me where is problem in code to navigation using Anchor Tag with encoded URL

Question

Problem is Url is getting encodede but "&" is not encoded

i want to open a page as a popup page using javascript in Anchor tag (.net 2.0) in below code "hotelname" is public variable on server side. when i use same code with button its working fine it encode complete value of "HotelName" variable but when i use same code with Anchor it encode all value of "HotelName" variable except "&" .

<a href='javascript:showWindow(<%# """MapShowDSHotelDetail.aspx?hotelname="& Server.UrlEncode(hotelname) & "&cityid=" & cityId & "&dspartnerid="& Container.DataItem("dspartnerid").toString()  &"""" %>,800,600)'>Show Detail</a>