Assigning file dynamically in Include directive?

Question

Is it possible to dynamically assign the file in Include directive?
If posibble how? The code below does not work.
<%
     String page_name = request.getParameter("num_id");
     if(page_name == null) page_name = "/body/that.html";
     if(page_name == "1") page_name = "/body/that.html";
     if(page_name == "4") page_name = "/body/that.html";
     if(page_name == "5") page_name = "/body/comment.html";
%>
<jsp:include page = "<%=page_name%>" />
If not any alternative on doing this?
More power!!!

Answer 1

There's always this...... and you know, of course, that you do'nt compare strings with ==, right?
<%
String page_name = request.getParameter("num_id");
if(page_name == null) {
%>
<jsp:include page = "/body/that.html" />
<%
} else if(page_name.equals("1")) {
%>
<jsp:include page = "/body/that.html" />
<%
} else if(page_name.equals("4")) {
%>
<jsp:include page = "/body/that.html"" />
<%
} else if(page_name.equals("5")) {
%>
<jsp:include page = "/body/comment.html" />
<%
%>