User form hides wrong information

[EGR2317]

I am creating a user form to hide certain options. I have coded the "OK" button to hide certain firlds depending on what I have checked. The problem is that when I click the "OK" button, it hides the wrong rows. It also hides rows when I click "OK" without anything being checked.

The code for the "OK" button is something like:
Private Sub Ok_Click()
If chkOption1 = True Then
Sheets("Sheet2").Select
Selection.Rows("3:4").Select
Selection.EntireRow.Hidden = True
ElseIf chkOption2 = True Then
Sheets("Sheet2").Select
Selection.Rows("5:6").Select
Selection.EntireRow.Hidden = True
End If
End Sub

The rows it hides for the first click of "OK" are always numbers that end in a 3 or 4. What do I need to do to fix this?