运行时错误“ 438”：对象不支持此属性或方法

Question

我正在使用Ms-Access做一个学校管理系统项目。我正在尝试创建多个用户的登录页面，但出现此错误。

  

运行时错误'438'：对象不支持此属性或方法

以下是VB代码。

Private Sub Command23_Click()

If IsNull(Me.txtUsername) Then
    MsgBox "Please enter Username", vbInformation, "Username Required"
ElseIf IsNull(Me.txtPassword) Then
    MsgBox "Please enter Password", vbInformation, "Password Required"
Else
    If Nz(DLookup("Password", "Users", "Username ='" & Me.txtUsername & "'"), "Password") = Me.txtPassword Then
        MsgBox "Welcome Back", vbInformation, "Access Allowed"
    Else
        MsgBox "Sorry ....Wrong Username and Password", vbExclamation, "Access Denied"
    End If
End If

End Sub