use lightbox in code behind

hi all,
i gave lightbox effect in .cs page but its not working, the code which i am using is
HtmlAnchor htmlanchor = new HtmlAnchor();
htmlanchor.HRef = "frmTooltip.aspx"; 
htmlanchor.Title = "Welcome"; //tooltip
htmlanchor.InnerText = "Welcome";
htmlanchor.Attributes.Add("rel", "lightbox");
here the page is redirecting to the frmTooltip.aspx page but lightbox effect is not working. it is opening as regular page.
and i have given javascript reference in aspx page are
<script language="javascript" type="text/javascript" src="Javascript/lightbox.js"></script>
    <script language="javascript" type="text/javascript" src="Javascript/prototype.js"></script>    
    <script language="javascript" type="text/javascript" ...