How to pass a value from WinForm (C#) to an altogether separate Javascript client chat application -

i have chat application in have client side(javascript) , server-side winforms. want pass value frmconsole.cs file converse.js file. there way can achieve this? using xmpp protocol connecting client , operator console , have own ejabberd server running same. example want pass string c# code javascript file:

private string getstringvalue() {   return "a string value"; } 

and javascript side code:

<script language="javascript" type="text/javascript">   var stringvalue = '<%=getstringvalue();%>';    alert(stringvalue); </script> 

i tried not throwing expected alert. in alert shows

<%=getstringvalue();%> 

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> <script type="text/javascript">      function showstring(){          var stringvalue = '<%=getstringvalue();%>';          alert(stringvalue);  </script> 

main body:

 scriptmanager.registerclientscriptblock(this, this.gettype(), "javascript", "javascript:showstring();", true);