Got "Permission Denied" error message when use WebServices Behavior

My application is written in ASP.NET 1.1, recently I need to add a new page to call send email web service which resides on the same server. Below is my source code:

<script type="text/javascript">
       var iCallID = 0;
       var service = null;
        function Init()
        {
           service = document.getElementById("service123");
             service.useService("http://localhost/SendEmail.asmx?WSDL","MyMath");           
        }
         &n ...