A/C sight glass on 2004 Maxima

[tsupernova]

I was just asked by a friend to look at her A/C in a 2004 Maxima. I took a quick look under the hood and found to suction and liquid service ports in plain view. Since I was just in a parking lot I didn't want to start ripping off engine panels, but just so I am prepared, does anyone know where the sight glass is on these? Also if it is low on refrigerant where the low pressure switch is too? Thanks in advance for the help.