Approve Trip Workflow

I have a couple of questions:

When the manager receives a notification in the UWL to Approve a 'Trip' he has several options.

Display Form and Need to correct trip facts has arisen.

1. How do I remove the 'Display Form'?

2. If I want to correct the Trip and click on the Need to correct trip facts has arisen button nothing happens. How do I correct the Trip?

To resolve point 2. to do I need to use BADi TRIP_WEB_CHECK?

Thanks

WB