Call Javascript from ASP

Working on a login ASP page and would like to have a JavaScript confirm pop-up box (with the Yes and Cancel buttons) appear after a successful login and when a condition is met?

Basically, if your condition is true, you write the Javascript code to the document, otherwise, you don't write the Javascript (or write a different message).

<%
If Now() > DateAdd("d",90,.Fields("DateLastPass")) Then
%>

<script type="text/javascript">

   confirm('Your message goes here');

</script>

<%
End If
%>

asp javascript