button question

I have a basic continuous form that a user can enter basic info about an 
accident eg Reference number, employee name, vehicle number etc etc. next
to 
each record there is a button that takes me to a larger form conected to
the 
same table, this is so a manager can add a more complete picture of the 
accidents events, i want this button to ask for a password before opening
the 
form. how can i do this? the buttons on click code is as follows:

Private Sub Command154_Click()
On Error GoTo Err_Command154_Click

    Dim stDocName As String
    Dim stLinkCriteria As String

    stDocName = "IncidentsEntryFRM"
    
    stLinkCriteria = "[Ref_No]=" & "'" & Me![Ref_No] & "'"
    DoCmd.OpenForm stDocName, , , stLinkCriteria

Exit_Command154_Click:
    Exit Sub

Err_Command154_Click:
    MsgBox Err.Description
    Resume Exit_Command154_Click
    
End Sub

Can you just add the code required to ask for a password please

Thanks