L80-m39- controlling actions via altitude

hi, i'm new to the forums, but I figured I would come here and hopefully get some help with this project I'm working on. I am working with a L80-M39 GPS unit. Based on the altitude of the GPS, I want to perform certain actions with a buzzer. Say if the altitude is greater than 60 meters or something like that, then the buzzer would buzz on and off for 3 seconds. If it was less than 60 meters, than it wouldn't buzz. Any examples, advice, or code that I could work off of for that? It would be greatly appreciated, thanks!
--Matthew

Download a GPS library such as TinyGPSplus and try the example programs in there. They should give you the idea.

The altitude given out by the GPS can vary by +/- 20M (or more) from the real sea level value depending on reception conditions, so dont plan on having a great deal of precision.