[javascript] JQuery - Set Attribute value

I have following HTML with two elements having the same name

<input type="hidden" name= "chk0" value="">
<input type="checkbox" name="chk0" value="true" disabled>

Through JQuery, I want to set the enable the checkbox. So, I am using something like this:

$('#chk0').attr("disabled",false);

But this doesn't work. I assume JQuery is getting confused with two elements having the same identical name. Unfortunatel, I cannot avoid using two different names because, when the form is posted, I want all the checkboxes to get posted (not just the ones that are checked). Hence I have to use hidden element with the same name.. So, back to the question, how can I enable the checkbox through JQuery in the above scenario? Is there a "type" parameter for attr which distingues hidden from checkbox?

Thanks

Use an ID to uniquely identify the checkbox. Your current example is trying to select the checkbox with an id of '#chk0':

<input type="checkbox" id="chk0" name="chk0" value="true" disabled>

$('#chk0').attr("disabled", "disabled");

You'll also need to remove the attribute for disabled to enable the checkbox. Something like:

$('#chk0').removeAttr("disabled");

See the docs for removeAttr

The value XHTML for disabling/enabling an input element is as follows:

<input type="checkbox" id="chk0" name="chk0" value="true" disabled="disabled" />
<input type="checkbox" id="chk0" name="chk0" value="true" />

Note that it's the absence of the disabled attribute that makes the input element enabled.

"True" and "False" do not work, to disable, set to value disabled.

$('.someElement').attr('disabled', 'disabled');

To enable, remove.

$('.someElement').removeAttr('disabled');

Also, don't worry about multiple items being selected, jQuery will operate on all of them that match. If you need just one you can use many things :first, :last, nth, etc.

You are using name and not id as other mention -- remember, if you use id valid xhtml requires the ids be unique.

You can add different classes to select, or select by type like this:

$('input[type="checkbox"]').removeAttr("disabled");

Seriously, just don't use jQuery for this. disabled is a boolean property of form elements that works perfectly in every major browser since 1997, and there is no possible way it could be simpler or more intuitive to change whether or not a form element is disabled.

The simplest way of getting a reference to the checkbox would be to give it an id. Here's my suggested HTML:

<input type="hidden" name="chk0" value="">
<input type="checkbox" name="chk0" id="chk0_checkbox" value="true" disabled>

And the line of JavaScript to make the check box enabled:

document.getElementById("chk0_checkbox").disabled = false;

If you prefer, you can instead use jQuery to get hold of the checkbox:

$("#chk0_checkbox")[0].disabled = false;

$("#chk0") is refering to an element with the id chk0. You might try adding id's to the elements. Ids are unique even though the names are the same so that in jQuery you can access a single element by it's id.