98 Jetta 2.0, Coolant light question

OK so, since i've had the car, for about 2 years, the coolant has been below the MIN line in the coolant reservoir, never had any problems. The coolant light first started flashing about 1 month ago, and it would come on in the morning after sitting over night, also weather has been pretty cold. Later on in the day, after i've driven in, wouldnt come back on. Now recently, no matter what, anytime, the coolant light flashes. Is it as simple as filling the coolant reservoir up between the MIN and MAX lines? any suggestions people?? i would greatly appreciate it! thanks!

Yes. Solid light means over heating. Flashing means low coolant level. I have a 98 Jetta and my light is very touchy. Gotta get the coolant level right in that center spot between min/max.