Confirmation letter format for sales employee

Dear All
Good day !!!
Kindly suggest suitable format of Confirmation letter format for specifically Sales Employee.
Ex- On what grounds we should evaluate their confirmation.
Please share required as soon as possible as it is required for an employee on urgent basis .
In advance thanks
Regards
Shilpi

Confirmation is based on performance. During Probation, employee performance has to be get it assessed by immediate boss, and vetted by the Senior Person in charge of sales. It can be on volumes or collection or both, excluding sales return if any.