Thermostat Replacement

Hi, I am new here, I have spent many hours reading here, but cant find exactly what I'm looking for, so please forgive me if this has already been posted... I currently have a Honeywell TH8320U1008 thermostat, it's acting all derpy, the lights go out when you try to change the temperature, the heat stays on for hours, etc. I have been told that I should start with the easiest thing to fix and go from there, so I went and bought a new thermostat, a Honeywell Rth221B1021, it is much smaller, much simpler and cheap. My old thermostat is completely unnecessary in my house, it is too much thermostat for the house. I have heat and AC, no heat pump, no fancy accessories, it is hooked up with 5 wires. Yellow, green, white, red and blue. Old thermostat is hooked up like so.. Attachment 42384 (http://www.doityourself.com/forum/attachments/thermostatic-controls/42384-thermostat-replacement-old-set-up.jpg) The new, cheaper, easier to use thermostat has this...