I agree with SLaks, but here you go
<asp:HyperLink id="hyperlink1" NavigateUrl="#" Text="" runat="server"/>
or you can alter the href using
hyperlink1.NavigateUrl = "#"; hyperlink1.Text = string.empty;
Just write <a href="#"></a>.
<a href="#"></a>
If that's what you want, you don't need a server-side control.
hyperlink1.NavigateUrl = "#"; orhyperlink1.attributes["href"] = "#"; or<asp:HyperLink NavigateUrl="#" runat="server" />