Bug 916523

Environment:
Server : English SLES11 SP3 64bit
Client : English Windows 7 SP1
Browser: IE11.0/FF35
Build  : novell-vibe-4.0.0-linux-20150203073953

Steps to Reproduce:
01.Log in to Vibe "http://vibe_hostname:8080" as the Vibe administrator;
02.Click the admin link in the upper-right corner of the page, then click the
   "Administration Console" icon;
03.In the "Management" section, click "Database Logs and File Archiving";
04.Input invalid value ,like 50.5,in "Automatically Delete Audit Trail Entries 
   Older Than:" box;
05.Click OK button,the button become gray and can't work;
06.Click Cancel button;
07.Open this window second time,then input valid value,like 50,in this box;
08.Click OK button,it can't work yet；
09.I have to log out,then log in,open this windows;
10.Input valid value,like 50,in this box,it can work well.

Expected Results:
01.It should throw error message and prevent when input invalid value;
02.OK button should work well.

Notes:
Bug is reproduced in "Automatically Delete Change Log Entries Older Than:" box.