Adding Comments in Workflow

Hi Experts,

I have a Requirement. There is a Scenario where I am Sending a Decision to a User for Approval/Rejection using a Workflow. This is being tested on User-Interface and not SAP-GUI.

"Now the Requirement is that when that User is taking a Decision, there he should be able to Enter some kind of Comments like Why he is Approving or Why he is Rejecting that Decision?"

How can I implement this Functionality in the Workflows?

Regards,

Kanika!