How to hide (or) Encrypt the Webpage name in URL

 Hi All,
I want to hid or encrypt the webpage name in url.
I am using MasterPage and treeview control in tree node navigate Url i am passing my Pagename
its display like this
http:\\Myserver\Product\Books.aspx?id=16
but I don't want to display my Pagename [Books.aspx] here
Like this http:\\Myserver\Product\abcdefsdfsk..   [Something like this]
Please help how do like this.
thanks
kumar..
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