Timer Creation

I'm trying to create a timer that counts down from 60 seconds, then when it reaches zero the game ends.

Function UpdateTimer()

Timer = MilliSecs()

If MilliSecs() > Timer + counter Then
	seconds = seconds - 1
	counter = counter + 1000
End If

If seconds = 0 Then Stop

End Function

counter is self-explanitory and seconds is used as the variable to print on-screen. When tested the seconds meter does not desend. If anyone can help me fix this code or suggest a better formula please do so.