Condition in XPath & Eval C# asp.net for Gridview or Datalist

Here I have if else if else 2 conditions

<%

#XPath("price").ToString() != "" ? "Sales Price:"+XPath("price").ToString() : XPath("listprice").ToString() != "" ? "List Price"+XPath("listprice").ToString() : "Too Low"%>

1 condition:

<%#XPath("detailurl") != "0" ? XPath("detailurl") : "sss"%>