下面是修改工作组用户密码的函数，调用时如果用于密码为空，请使用""，不要使用null，两者不同。：）
Function CheckUserPasswordInGroup(UserName As String,_
oldPassword As String, newPassword As String) As Boolean
On Error GoTo ChkErr
Dim wk As DAO.Workspace, Ur As DAO.User, i As Integer, Found As Boolean
CheckUserPasswordInGroup = False
Found = False
Set wk = DBEngine.CreateWorkspace("", "Admin", "")
'//要特别注意上面一句，必须使用拥有数据库管理权限的用户名和密码打开工作区！
'//下面一段是查找用户名是否存在，如果存在，修改密码，不存在出错报告。
For i = 0 To wk.Users.Count - 1
If wk.Users(i).Name = UserName Then
Set Ur = wk.Users(i)
Found = True
Ur.newPassword oldPassword, newPassword
Exit For
End If
Next i
If Not Found Then
MsgBox "'" & UserName & "' 不是一个有效的用户名！",_
vbExclamation, "艾赛思应用网"
CheckUserPasswordInGroup = False
Exit Function
End If
CheckUserPasswordInGroup = True
Exit Function
ChkErr:
MsgBox "'" & UserName & "' 用户密码修改失败！",_
vbExclamation, "艾赛思应用网"
CheckUserPasswordInGroup = False
End Function