Bob,
You could always make a sessionScope managed bean and store the value in a hash map in the bean. A hash map is simply a key/value pair. So once you setup your bean you could access it via SSJS like:
MyBean.setFieldValue(unid,value);
and to get the value:
MyBean.getFieldValue(unid);
This is assuming you have methods in the bean called setFieldValue and getFieldValue that would just get values from the stored hash map and add values to the hash map. Of course if it's more than just one field that's editable you would need to add additional logic for that. Here are some excellent articles on using managed beans:
http://www.mindoo.de/web/blog.nsf/dx/16.07.2009095816KLEBCY.htm?opendocument&comments
http://xpages.info/XPagesHome.nsf/Entry.xsp?documentId=4B1849D9F0F5EDC0852578CB0066BD27
http://xmage.gbs.com/blog.nsf/d6plinks/TTRY-8GK6K7 - This is more the theory/introduction to managed beans
http://blog.mindoo.com/web/blog.nsf/dx/18.03.2011104725KLEDH8.htm
You could also setup a hash map via SSJS in a scoped variable and skip the managed bean part:
var myMap:java.util.HashMap = new java.util.HashMap();
sessionScope.put("myValueMap",myMap);
sessionScope.get("myValueMap").put(unid,value);
var myValue = sessionScope.get("myValueMap").get(unid);
Either way should provide a fairly robust solution. However using a bean would provide more room for expansion and data manipulation than a pure SSJS solution, but it does require a bit more time putting it all together.
HTH
Keith