Timer Control - Calling Function At 8 To 11 Seconds

I have successfully set up a timer in visual basic, see the code below. My timer uses case statements and at specific case/time it calls a function, 'ShuttleA'. 'ShuttleA' function, is a function that 'getskeystate', which inturn from the user interface tallies a response in a text box. My problem is that the program runs fine when calling the function at eg; at 10 seconds, case 10. But I want to be able to call the function e.g., at 8 seconds to 11 seconds. Or create a tolerance of e.g., 1 second either side of e.g., 10.

PrivateSub Timer1_Tick(ByVal sender As System.Object,ByVal eAs System.EventArgs)Handles Timer1.Tick
Dim secondsAsInteger
seconds += 1
Label1.Text = seconds
SelectCase seconds
[Code] .....