Showing Framerate with DrawText()?

I found this here on the forum:

Local FPS_Counter:Int
Local FPS_Counter_Time:Int
Local FPS:Int
FPS_Counter=FPS_Counter+1
If FPS_Counter_time+1000 =< MilliSecs()
FPS=FPS_Counter' <- Frames/Sec
FPS_Counter=0
FPS_Counter_time=MilliSecs()
EndIf
DrawText "Current FPS: "+FPS,20,20

but it doesnt seem to work?