Asp.Net(C#) inline coding one more eval Merge

How to make one more eval merge ?

<asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Eval("Name"),Eval("Surname"),Ev开发者_高级运维al("Mail")%>'/>

---

Try

<asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Eval("Name") + "," + Eval("Surname") + "," + Eval("Mail")%>'/>