2004 Dodge Stratus Overheating

My 2004 Dodge Stratus is overheating. I changed the thermostat thinking that this was probably the problem. It then overheated again. I then noticed that the cooling system fan, nor the AC system fan was coming on.

It only gets hot when sitting. When I start moving, it cools down. Any idea why neither fan would be blowing? I am guessing that the fans not blowing is the reason that it is overheating.

Thanks,

Randy