Taking a cue from Andrew's post, I tried the following:
a = enterNumber(?prompts list("Enter a number"))
printf("That number squared is %f\n" a**2)
However, when I type test in the CIW, the routine proceeds without stopping for user input (this is not the final application). If you try to enter a number it does not compute its squared value. It simply blows right past all of that. if you type, a, in the CIW, it is undefined but since my procedure made it global, it is evident that a was never assigned.