# Comparing selection of a drop down using ajax **URL:** \ **Category:** Rails\ **Created:** [May 1, 2008, 4:46am UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354 "2008-05-01T04:46:00Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![rushnosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/58956e/32.png) [@rushnosh](https://www.ruby-forum.com/u/rushnosh)\ **Post date:** [May 1, 2008, 4:46am UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354/1 "2008-05-01T04:46:00Z")
I am very new to ruby and since my javscript skills are zero I was wondering if this could be done. I have a drop down. When the user makes a selection I would like to make a call with observe\_field. Can I then check to see if the selection the user made from the drop down menu is in a another array that keep track of what the user has selected. In the array that is checked against will simply add 1 next to the item if it is not in the list. That is the user is selecting it for the first time. My English is not very good so I hope this makes sense. Can someone give me some guidance on this. ---
**Author:** ![rushnosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/58956e/32.png) [@rushnosh](https://www.ruby-forum.com/u/rushnosh)\ **Post date:** [May 1, 2008, 5:31am UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354/2 "2008-05-01T05:31:02Z")
yeah you can get the value of what the select is set at and add it to a javascript variable or what not. Google for select javascript. ---
**Author:** ![rushnosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/58956e/32.png) [@rushnosh](https://www.ruby-forum.com/u/rushnosh)\ **Post date:** [May 1, 2008, 7:30am UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354/3 "2008-05-01T07:30:17Z")
So I used \<%= observe\_field :id\_of\_select, url =\> {action =\> “add”}, :frequency =\> 0.25 %\> this is below the select tag when I choose and item from the drop down it does absolutely nothing. I examined it in firebug and I don’t see anything either. View of the source shows that it has selected the proper id of the drop down. ---
**Author:** ![rushnosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/58956e/32.png) [@rushnosh](https://www.ruby-forum.com/u/rushnosh)\ **Post date:** [May 1, 2008, 10:16pm UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354/4 "2008-05-01T22:16:11Z")
I’m not sure how to do rjs with observe\_field. ---
**Author:** ![rushnosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/58956e/32.png) [@rushnosh](https://www.ruby-forum.com/u/rushnosh)\ **Post date:** [May 1, 2008, 8:27am UTC](https://www.ruby-forum.com/t/comparing-selection-of-a-drop-down-using-ajax/136354/5 "2008-05-01T08:27:00Z")
I got something to happen in firebug, but it is calling function 3 or 4 times while the user goes down the drop down menu. Also I can not get it do anything with .js file no out come , tried a simple page.insert. Is observe\_field the correct method? I have map.connect ‘:controller/:action/:id.:format’ below it I have a catch all map.connect ‘\*path’, :controller =\> ‘user’, :action =\> ‘login’