Hi tullio0106,
I don’t know if you tested my code example that I send but let me clarify it a bit.
window.onload in this case its executed when the whole page to be completely loaded with including all dependent resources such as stylesheets and images but one important thing to note here that it doesn’t fire any events at all and we just add an event listener onchange for every combobox and from it you can access the changed element id for example and I didn’t get the modified code from you.
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team