I'm using a jsp which has this code, only:

Code:
<%@page import="java.text.*" %>
<%@page import="java.util.*" %>
<%@ page contentType="text/html;charset=windows-1252"%>

<HTML>
  <BODY>
	  <TEXTAREA name="textarea" rows=12 cols='15' style="TEXT-ALIGN: right"></TEXTAREA>
	  <BR>
	  <INPUT value='0' type="text" onBlur="numFormat(txtbox.value)" name="txtbox">
  </BODY>
</HTML>
As you can see I have a numFormat() function .. but I want to have this function in an external file. Which extension should this file be? .class? .js? or other? And how can I connect the .jsp code to the external file?

Thanks!