Close Opportunity as Lost dialog in Portal

Question

I require the same functionality in the Partner Portal as in Dynamics CRM. In Dynamics CRM, when a user close an Opportunity as Lost, a dialog appears to fill in the Description why the opportunity is lost. I need a similar Dialog on the Partner Portal when the Opportunity is Closes as Lost

Screenshot below is from the Dynamics CRM site:

Answer 1

We have to develop a custom form and mimic this functionality on our own, as this is CRM functionality, and not available in portals.

Similar discussion in Dynamics community forum:

When you close an opportunity within CRM, you only see the Opportunity close dialog.

The opportunity close form is not used for any CRUD operation, it is also tricky to pass opportunity id as it gets modified during the process.

I'd recommend using a new custom form which updates the required attributes of opportunity Entity and maybe use a Workflow to close the opportunity on submit of this form.