Aj Raval is the Head of Agency Environment who was granted a cash advance for travel to attend a seminar regarding the effects of using dolomite in rehabilitating Manila Bay Upon liquidating, it was found out that the disbursement voucher for that transaction lacks the required supporting documents. As the accountant of the Agency Environment, Raval went into your office, locked the door and told you about the transaction.

What would you advise Raval and what necessary documents you need to submit in order to make the disbursement valid?