# Whether the "onclick" event works in sidebar? **URL:** \ **Category:** Development\ **Created:** [March 5, 2018, 12:32pm UTC](https://discourse.mozilla.org/t/whether-the-onclick-event-works-in-sidebar/26287 "2018-03-05T12:32:04Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![d11](https://avatars.discourse-cdn.com/v4/letter/d/47e85d/32.png) [@d11](https://discourse.mozilla.org/u/d11)\ **Post date:** [March 5, 2018, 12:32pm UTC](https://discourse.mozilla.org/t/whether-the-onclick-event-works-in-sidebar/26287/1 "2018-03-05T12:32:04Z")
Hi! In Mozilla add-ons (created with WebExtention) I need put some button on the sidebar and add “onclik” event on it. I wrot simple code in sidebar HTML file: ```

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``` where file panel.js has such content: ``` function showNext() { alert("ok"); } ``` But when I press button “Prev”, “alert” window, doesn’t appear. I have tried to make even more simply and used only sidebar HTML file: ```

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``` …same result ( What wrong? P.S. sidebar is shown correctly ![%D0%B8%D0%B7%D0%BE%D0%B1%D1%80%D0%B0%D0%B6%D0%B5%D0%BD%D0%B8%D0%B5](https://us1.discourse-cdn.com/flex001/uploads/mozilla/original/3X/a/0/a057feb6112a8aeb289a0daa55ec68f8c4f27253.png) ---
**Author:** ![freaktechnik](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/freaktechnik/32/37766_2.png) [@freaktechnik](https://discourse.mozilla.org/u/freaktechnik)\ **Post date:** [March 5, 2018, 2:12pm UTC](https://discourse.mozilla.org/t/whether-the-onclick-event-works-in-sidebar/26287/2 "2018-03-05T14:12:05Z")
Inline scripts (including on\* event attributes) are not allowed in extensions. Add your listener in your JS with `addEventListener` instead. ---
**Author:** ![d11](https://avatars.discourse-cdn.com/v4/letter/d/47e85d/32.png) [@d11](https://discourse.mozilla.org/u/d11)\ **Post date:** [March 6, 2018, 4:41am UTC](https://discourse.mozilla.org/t/whether-the-onclick-event-works-in-sidebar/26287/3 "2018-03-06T04:41:33Z")
Many thanks, Martin!