Help: append two data fileds in HyperLink string

[milo]

The following line can product this link: summary.aspx?ID=123

<asp:HyperLink id=lnkSummary runat="server" Text="Summary" NavigateUrl='<%#
"summary.aspx?ID=" &amp; DataBinder.Eval(Container.DataItem,"ID")%>'>

I need to use a second value form the data field called SID to produce a
link like:
summary?ID=123&SID=456 (SID=456)

How?