How to use Javascript to get ASP.NEt Web Forms label's value?

Question

I have the following label control:

<asp:Label ForeColor="DarkGreen" runat="server" ID="lblStatus"></asp:Label>

Its value is filled in the Page_Load event.

I attached the following Javascript (placed at the end of the page, not Master page):

function Validate() {
        var lblObj = document.getElementById('<%=lblStatus.ClientID%>');
        alert(lblObj.value);
        if (lblObj.value == "Replaced" || lblObj.value == 'Trashed' || lblObj.value == "Internal Use") {

            alert("Products with" + lblObj.value + "status cannot be reserved");
            return false;
        }
    }

The alert(lblObj.value) displays a popup with text "undefined". How can I fix this problem? Please, I tried many combinations for placing the JavaScript but no luck! Thanks

UPDATE

Browser soruce code:

<span id="ctl00__main_lblStatus" style="color:DarkGreen;">Available</span></td>

First line of Validate JS function:

function Validate() {
        var lblObj = document.getElementById('ctl00__main_lblStatus');

you want to set or to get? question's title and content mismatch. — Davide Piras
– Davide Piras, Commented Sep 15, 2011 at 13:17
@CiccioMiami : can you port the result of validate function's first line by view source ? — Canavar
– Canavar, Commented Sep 15, 2011 at 13:28
@Davide Piras, see update. However if you want to laugh I just tried the script in IE and it works. It does not work on Firefox tough, I don't mind about IE — CiccioMiami
– CiccioMiami, Commented Sep 15, 2011 at 13:37
@CiccioMiami, use JQuery and will run in all browsers and platforms, something like: $("#" + Control.ClientId).next().text(); see here: stackoverflow.com/questions/1286317/… — Davide Piras
– Davide Piras, Commented Sep 15, 2011 at 13:40

Daniel A. White · Accepted Answer · 2011-09-15 13:15:43Z

5

labels don't have a value. They have innerHTML and innerText.

answered Sep 15, 2011 at 13:15

Daniel A. White

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4 Comments

CiccioMiami Over a year ago

@ Daniel A. White: I tried innerText and still gives me undefined

Daniel A. White Over a year ago

Is the client id being printed ok?

CiccioMiami Over a year ago

yes I already compared control and javascript code and they are the same

CiccioMiami Over a year ago

However if you want to laugh I just tried the script in IE and it works. It does not work on Firefox tough, I don't mind about IE

Community · Accepted Answer · 2017-05-23 12:22:55Z

4

Use JQuery and it will run in all browsers and platforms, something like:

$('#<%= lblStatus.ClientID %>').next().text();

source: JQuery: getting the value/text/innerHtml of a checkbox in an ASP.NET CheckBoxList control

edited May 23, 2017 at 12:22

CommunityBot

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answered Sep 15, 2011 at 14:58

Davide Piras

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Comments

Canavar · Accepted Answer · 2011-09-15 13:17:30Z

4

Label server control renders as span. So you should get it's content by innerText. try this :

alert(lblObj.innerText);

answered Sep 15, 2011 at 13:17

Canavar

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1 Comment

CiccioMiami Over a year ago

However if you want to laugh I just tried the script in IE and it works. It does not work on Firefox tough, I don't mind about IE

slobodans · Accepted Answer · 2011-09-15 13:24:04Z

2

ASP.NET label server control will be rendered in complex HTML output. Like:

<span id="ctl00_ctl00_ContentPlaceHolder1_BodyPlaceHolder_lblLanguage0">
 <label class="inputText">English</label>
</span>

When you use getElementById you will get span. But to set value via javascript you have to access inner label object

answered Sep 15, 2011 at 13:24

slobodans

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Comments

raje · Accepted Answer · 2013-12-19 07:14:40Z

1

try this

<script language="javascript" type="text/javascript">
function getlabelvalue()
{
   var value1 = document.getElementById('<%=labelID.ClientID%>').value;
            if (value1.length < 1)
                value1 = 0;
}    
 </script>

answered Dec 19, 2013 at 7:14

raje

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Comments

Enkode · Accepted Answer · 2016-08-19 04:58:45Z

1

With jquery you need to use the html method.

var g = $('#<%=lblStatus.ClientID%>').html();

These will NOT work with jquery:

$('#<%=lblStatus.ClientID%>').innerText
$('#<%=lblStatus.ClientID%>').innerHTML
$('#<%=lblStatus.ClientID%>').val()

answered Aug 19, 2016 at 4:58

Enkode

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