You have just to create a timer and then add an handler for its Elapsed event. The parameter to pass to the constructor is the interval of the timer (milliseconds).
Dim Time As New System.Timers.Timer(5000)
AddHandler Time.Elapsed, AddressOf Timer_Elapsed
Time.Start()
In the
Timer_Elapsed
sub you put the code that must be executed every tick of the timer:
Private Sub Timer_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs)
MsgBox("Time is up!")
End Sub