# Ajax question...need some help

**URL:** <https://discuss.rubyonrails.org/t/ajax-question-need-some-help/17136>\
**Category:** rubyonrails-talk\
**Created:** [August 17, 2007, 11:23pm UTC](https://discuss.rubyonrails.org/t/ajax-question-need-some-help/17136 "2007-08-17T23:23:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![William\_Pratt](https://avatars.discourse-cdn.com/v4/letter/w/9dc877/32.png) [@William\_Pratt](https://discuss.rubyonrails.org/u/William_Pratt)\
**Post date:** [August 17, 2007, 11:23pm UTC](https://discuss.rubyonrails.org/t/ajax-question-need-some-help/17136/1 "2007-08-17T23:23:39Z")

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I would use an observer like this:

\<%= select\_tag :foo, [1,2,3,4], 1) %\> \<%= observe\_field :foo, :url =\> {:action =\> :bar}, :with =\> 'foo' -%\>

Make sure you include the :with =\> 'foo' as that will become params[foo] and will be equal to the selected value in the select

see: [http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html#M000535](http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html#M000535)

Mix Mix wrote: