Help needed to enhance a HTML prompt

Here is a demo of the old HTML prompt.

I copy a source term and a target term from my translation editor and via some algorithms I generate all declensions for three German genders and two Dutch genders.

But sometimes the algorithm is wrong and I have to override the generated results in the left or right box. E.g. the algorithm thinks that the Dutch is feminine like the German, while it actually is neutral. Then I click the het button.