1. open a new xform
2. open the datanavigator
3. open the add element dialog
4. click on one condition button
5. click on Edit Namespaces
6. insert any new namespace
7. click on the add button 
8. insert any new namespace
9. click OK
10. click OK
11. click on Edit Namespaces
12. click on edit
13. change the name of the prefix
14. click OK
15. click OK
16. click on Edit Namespaces
==>> now you have 2 namespaces. One with the old name and one with the new name.