# Add onchange attribute to collection\_select

**URL:** <https://www.ruby-forum.com/t/add-onchange-attribute-to-collection-select/182183>\
**Category:** Rails\
**Created:** [January 24, 2010, 3:20pm UTC](https://www.ruby-forum.com/t/add-onchange-attribute-to-collection-select/182183 "2010-01-24T15:20:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![M\_I\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/839c29/32.png) [@M\_I\_R](https://www.ruby-forum.com/u/M_I_R)\
**Post date:** [January 24, 2010, 3:20pm UTC](https://www.ruby-forum.com/t/add-onchange-attribute-to-collection-select/182183/1 "2010-01-24T15:20:19Z")

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Hi,  
I am creating a dropdown list with the follwoing code which work  
perfectly

\<%= f.collection\_select (:building\_id,  
@buildings, :id , :build\_title , :prompt =\> “select”) %\>

but i want to use ONCHANGE attribute to it how will i do this ,  
please help i am new to RoR

---

<div class="post-metadata">

**Author:** ![M\_I\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/839c29/32.png) [@M\_I\_R](https://www.ruby-forum.com/u/M_I_R)\
**Post date:** [January 24, 2010, 8:31pm UTC](https://www.ruby-forum.com/t/add-onchange-attribute-to-collection-select/182183/2 "2010-01-24T20:31:07Z")

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Perhaps observe\_field method helps you:

[http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html#M001654](http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html#M001654)

2010/1/24 M I R [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

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