# Ajax for making one form element dependent on another

**URL:** <https://www.ruby-forum.com/t/ajax-for-making-one-form-element-dependent-on-another/106703>\
**Category:** Rails\
**Created:** [June 13, 2007, 1:54pm UTC](https://www.ruby-forum.com/t/ajax-for-making-one-form-element-dependent-on-another/106703 "2007-06-13T13:54:07Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![rpm13](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/3d9bf3/32.png) [@rpm13](https://www.ruby-forum.com/u/rpm13)\
**Post date:** [June 13, 2007, 1:54pm UTC](https://www.ruby-forum.com/t/ajax-for-making-one-form-element-dependent-on-another/106703/1 "2007-06-13T13:54:07Z")

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I have a list of pairs say [[1, ‘a’], [2, ‘b’],…

I need to make a form in which the numbers 1,2 etc would be a selection  
list in one field and the [a,b…] would be autofilled in ajax mode.

Is this easy/possible?