javascript message on web app

[classy_dog]

In a vb.net 2010 web form application, I have the following code:

<%@ Page Title="" Language="VB" MasterPageFile="~/MasterPage.master" AutoEventWireup="false" CodeFile="default.aspx.vb" Inherits="attendanceletters_default" %>
<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<script src="../scripts/jquery-1.3.2.js" type="text/javascript"></script>
<script src="../scripts/jquery-ui-1.7.2.custom.min.js" type="text/javascript"></script>
<%If (False) Then%>
<script src="../scripts/jquery-1.3.2.js" type="text/javascript"></script>
<% End If%>
<script src="../scripts/site.js" type="text/javascript"></script>
<script src="../scripts/json2.js" type="text/javascript"></script>
function GetStudentLetterTemplate(schoolyear, schoolnum, milestone, studentlink, language, semester) {

        alert('schoolyear: ' + schoolyear + 'schoolnum: ' + schoolnum + 'milestone: ' + milestone + 'studentlink: ' + studentlink + 'language: ' + language + 'semester: ' + semester);
         if (milestone == '999') {
             alert('You have selected student(s) having more than one CAIP entry for the current school year');
           return;
        }

}

I want to display a javascript alert message in production when an error condition exists. The code listed above works in a development envirnonment, but the code would not deploy to a test app server. Thus can you show me what I can do to fix the code listed above? If not, would you show me what I can do in a production environment to have a warning message displayed to a user with the least amount of extra code? I do not care how the warning message is displayed, I just want a warning message to be displayed.