how to close userform using commndbutton and set automatic close at certain time

hi,
i have a userform and i want to set it if user click close, it will unload the userform but if user didnt close or the userform is idle for 1min, the userform will automatically close.

i have try this

Private Sub UserForm_Activate()
startTimer = Timer

Do While Timer < (startTimer + 60)
DoEvents
Loop
Unload Me

End Sub


and at every button in userform i try this

Private Sub ComboBoxx4_Change()
startTimer = Timer
End sub


Sub CommandButton1_Click()
'close button
startTimer = Timer
Unload Me
End Sub


but the codes doesnt work.it will close in 1 min even the userform is not idle.