Hello Mick, thanks for all the effort you put into this, very much appreciated!
But this isn’t the ‘Fill out this field’ pop-up that I meant, so I added a screenshot of the pop-up that I’m talking about (this is the standard pop-up that shows when you click on Send when you haven’t filled in a required field).
Ah ! Thanks for the reply Rebb. Well I haven’t constructed a form of this type so clearly I misunderstood. Nonetheless, I will be interested to see what the correct answer is !
@Mr_Fozzie: thank you very much, that was the solution.
I set my browser to Dutch and that little pop-up changed indeed to Dutch. So you’re right, I was looking for a solution in Sparkle while I should have been looking elsewhere.
Lots of thanks to both of you for your help, my problem is resolved!