If you did go ahead and try the calculator before we had entered all the scripts it needed, you most likely would have got to see the script debugging in action. Hopefully you managed to cope with what you saw; it can be overwhelming at first. The following screenshot is what it would have looked like:
Most of what you see is the same as when you edit scripts, but if you do see the debug variation you are actually in a paused state, a freeze frame of the program as it runs. In this example the program stopped because line 46 is looking for a field named
dis play, and there isn't such a field, it should be
The error message at the ...