Compatibility problem when add actions to customized object

Hi,

I followed sample "chassisRackVSphere-ui" in 5.5 vshpere-client-sdk to add actions(e.g. add, edit, delete) for my own objects.

It worked well in my 5.5 environment. But the Add button didn't display in 5.1 web client.

Is there any idea that I can make it show up in 5.1 web client or is there a way to add an "Add" action in 5.1 when no object is selected?

In sample "chassis-ui" of 5.1 vshpere-client-sdk, if no object is selected, the Add button don't show up. Obviously it doesn't make sense.

Thanks,

Vicky