Is it possible show pop-up on creating issue?

[Oleksii Dziapko]

Hi there, could anyone give me advise how can I run javascript from behavior or another way to show pop-up?
After custom field (date field) was filled by user I'd like to notify the reporter of issue that the date was exceeded.
Adding a description and/or help text doesn't work for me.
Thanks in advance.

[Danyal Iqbal]

You can add your javascript to the description of a text field or in the announcement banner.

See: https://confluence.atlassian.com/jirakb/how-to-display-a-field-based-on-another-field-s-selection-649921383.html for reference.

P.S: Popups are annoying. Nobody likes them :) Please reconsider.

[Oleksii Dziapko]

Thank you, @Danyal Iqbal, I know about such approach, but I've noticed that javascript very often works inappropriate way or it doesn't work at all. So, that's why I prefer to use groovy script.