Description of problem:
If we want change the primary interface using WebUI, we get ISE.

Version-Release number of selected component (if applicable):
SW 2.1
SW 2.2

How reproducible:
100%

Steps to Reproduce:
1. Open HW detail of system (/rhn/systems/details/SystemHardware.do?sid=1000010000)
2. Change the primary interface and click on the button "Update Properties"

Actual results:
ISE

Expected results:
without exception

Additional info:
On this page, there is HTML structure mish-mash. 
The form tag is open in one block and closed in other block. This is problem, because, the browser automatically close the from tag and the selectbox is not inside. It means, the selectbox was not sent.
When I  fix HTML structure, all is OK.

BTW: On this page, there is a unopened div tag.