Pausing in wxMaxima



I'm using wxMaxima to create a wxm file that will be used by students. One 
step is to use solve. In the next step, the solution is to be applied. For 
some parameter values, solve yields multiple solutions, typically one of 
which is real and positive.
I'd like to be able to have students use wxMaxima's ctrl-r (evaluate all 
cells) but insert a pause so that, before executing the second step above, 
the student can provide the proper index from the list of solutions.

Can this be done?

Thanks,

Wilson Mixon