VBA OnClick -- Prompting User For More Than One Required Field

I'm using VBA to prompt users for two required fields. One I can do, but with more than one I get into issues like only 1 message box appearing at a time. If both fields are blank I want both messages to appear. Here's my code, it's in an On click function:

If IsNull(req_file_num) = True Then
MsgBox "Required field: File #. The appropriate file number must be entered before this PO's status can be changed to Filed."
GoTo Err_Command_158_Click2
End If

If Not [req_filed_date] Then
[req_process_status_rec_id] = 8

MsgBox "Your changes have been processed. This purchase order now has a status of Filed."
DoCmd.Close acForm, "frm_req_file"
GoTo Err_Command_158_Click2
Else: MsgBox "Required field: File Date. The appropriate date must be entered before this PO's status can be changed to Filed."
GoTo Err_Command_158_Click2

End If

Err_Command_158_Click2:
End Sub


I realize that it only shows one message box because I have the GoTo Err_Command_158_Click2 command, but I couldn't figure out how else to keep it from continuing through the code. If both "req_file_num" and "req_filed_date" are null, then I don't want the "req_process_status_rec_id" to change to 8 and have the form close.

Thanks for your help!