# Changing an element's class via AJAX

**URL:** <https://www.ruby-forum.com/t/changing-an-elements-class-via-ajax/147204>\
**Category:** Rails\
**Created:** [August 29, 2008, 10:37am UTC](https://www.ruby-forum.com/t/changing-an-elements-class-via-ajax/147204 "2008-08-29T10:37:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Franz\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/ecb155/32.png) [@Franz\_S](https://www.ruby-forum.com/u/Franz_S)\
**Post date:** [August 29, 2008, 10:37am UTC](https://www.ruby-forum.com/t/changing-an-elements-class-via-ajax/147204/1 "2008-08-29T10:37:45Z")

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Greetings folks,

Does anyone know how I can modify a DOM element’s  
class on the fly via AJAX? Is this even possible?

I basically want to toggle a background color after the  
user updates a pass/fail attribute on one of my models.

Thanks in advance.

Regards,  
Franz

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<div class="post-metadata">

**Author:** ![Franz\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/ecb155/32.png) [@Franz\_S](https://www.ruby-forum.com/u/Franz_S)\
**Post date:** [August 29, 2008, 10:42am UTC](https://www.ruby-forum.com/t/changing-an-elements-class-via-ajax/147204/2 "2008-08-29T10:42:26Z")

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On Aug 29, 9:37 am, “Franz S.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Greetings folks,
> 
> Does anyone know how I can modify a DOM element’s  
> class on the fly via AJAX? Is this even possible?
> 
> I basically want to toggle a background color after the  
> user updates a pass/fail attribute on one of my models.

Use prototype addClassName, removeClassName, toggleClassName utilities  
or just fiddle with the element’s className directly

Fred