Script Code and Template Text editors; "Compare" button displays warning if there is nothing to compare

Script Code and Template Text editors which are available on various forms have a "Show/ hide compare panel" button.

When the right-hand "compare" panel is displayed, a "Compare" button below it allows the content of both panels to be compared.

A message will be displayed if either panel is empty as there is nothing to compare. The message is "Both panels must contain text for a valid comparison.".