Question

Get Selected Value of DropDownList using Javascript

Asked by: davidcahan

This shouldn't be hard

Here's my Javascript code:

var dropdown = document.getElementById(<%= ddlStateID.ClientID %>);
var text = dropdown.options[dropdown.selectedIndex].value;

and heres my dropdownlist control:

<asp:DropDownList ID="ddlCountryID" onChange="SelectStates(this)" runat="server"></asp:DropDownList>

but everytime i change the selection i get this error:
Error: 'ct100_ContentPlaceHolder1_ddlCountryID' is undefined.

I think it's just how i'm calling the options or something in the javascript...i've seen this before, fixed this before, but can't find the code where i did it.  Big deadline on monday and i'm going nuts.

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Asked On
2008-01-11 at 19:01:16ID23077457
Tags

javascript

,

value

,

get

,

dropdownlist

,

using

Topic

Programming for ASP.NET

Participating Experts
2
Points
500
Comments
8

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Answers

 

by: thirdPosted on 2008-01-11 at 19:07:36ID: 20642487

isn't this supposed to be

<%= ddlCountryID.ClientID %>

since your dropdown is

<asp:DropDownList ID="ddlCountryID" onChange="SelectStates(this)" runat="server"></asp:DropDownList>

 

by: thirdPosted on 2008-01-11 at 19:08:58ID: 20642491

another way is run your aspx page from a browser and check the assigned id of your dropdown. substitute that id to your javascript function.

 

by: thirdPosted on 2008-01-11 at 19:13:43ID: 20642515

also, I think you missed the single quotes.

var dropdown = document.getElementById('<%=ddlCountryID.ClientID%>');

 

by: davidcahanPosted on 2008-01-11 at 19:14:39ID: 20642520

yea, it is ddlCountryID.ClientID.  I pasted my code from an earlier undo.

 

by: davidcahanPosted on 2008-01-11 at 19:24:57ID: 20642580

I found my code to do it.  It's just a slight wrinkle from other syntax i've seen posted on other sites.  None of that stuff ever worked, but this does:

var text = document.getElementById('<%= ddlCountryID.ClientID %>').options[document.getElementById('<%= ddlCountryID.ClientID %>').selectedIndex].value;

                                              
1:

Select allOpen in new window

 

by: thirdPosted on 2008-01-11 at 19:26:36ID: 20642593

yup if you have read my last post.

 

by: davidcahanPosted on 2008-01-11 at 20:01:34ID: 31421035

I'll give ya the points cause you helped get me motivated enough to find my own code, plus your answer was in the right direction

 

by: manojkumarpsPosted on 2009-10-20 at 00:07:32ID: 25611609

var ddlist=document.getElementById('<%=ddlCountryID.ClientID%>');
        var val = ddlist.options[ddlist.selectedIndex].value;
        var text = ddlist.options[ddlist.selectedIndex].text;

Where ddlCountryID is the comboBox Name

20120131-EE-VQP-002

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