Refresh on webdynpro causes error

Hi Experts,

I have a view on my webdynpro(java) page. The first time display is good. But when i click on refresh button of the

browser, there is an exception. The exception says "Instance of view controller View does not exist".

Is there any event triggered on browser refresh that iam not catching? Can you help me?

Thanks,

Satish Challa.