BAdi implementation for switch document

Hi,

We need some custom fields in the other data tab of switch document.

We have been trying to implement the BAdi ISU_IDE_SWITCHDOC but after implementing/activating also the control was going to the default implementation class.

As per i understand after implementing & activating an BAdi implementation the control should go through the implemented class methods.

Please let me know the steps for adding some custom fields in the other data tab of switch document.

Regards,

Deepak