Re-set a list when re-visiting a slide

Hello all,

I'm working on a project and I keep on getting duplications of a list of selected items. How can this be avoided?

On the 1st slide students use textboxes and type some comments in.

On the 2nd slide I've used references to display the list of all the typed comments. On the 2nd slide students can select or de-select comments if they consider these comments to be related to a certain topic. I've used states of the textboxes that contain the reference to each comment to show if one is selected or de-selected.

On the 3rd slide I've used Javascript to get a list of all the comments that were selected on the 2nd slide, so students can decide what are their next action for each of these comments.

When a student re-visits 2nd slide they can choose to de-select a comment that was previously selected, or to select another that they did not select originally.

Then when a student re-visits the 3rd slide they get the originally selected list, and the new list of their selection. Thus, there is a duplication.

How can I remove the originally selected list when a student re-visits the 3rd slide?

Thank you for your help in advance!