Edit: Missed the msg from MourningStar, Glad you got it working... no credit needed for my part.
Yeah, we don't expect credit for correcting code, just as Yincognito said...
From your screen shot, something must have gone wrong in your 'cut/paste'...
Try the package posted above by Yincognito which should give you everything.
The way the scroll works is by adding Mouse action bangs to [MeterTemperature] that set a new value for the 'Scale' variable, clamping it between 0.1 and 3. If you look at the code I posted you will see the mouse scroll action bangs at the end of that section.
I can lead you in the right direction, but some study of the documentation
You may find performing the basic tutorials
helpful to understand how measures, meters , and action bangs work.
Keep learning, it is not too difficult and will get easier the more you learn.