Question

I have a very simple form for uploading a file. In the form, there’s a dropdown menu where you can choose a category for the file you’re uploading. I also have another checkbox which is by default unchecked. How can I make it so that if the third in the dropdown is selected, the checkbox is automatically checked and disabled? Thanks for your help.

Answer 1

Try something like this:

if ($('#selectboxid').val() === $('#selectboxid option:eq(2)').val()) {
    $('#checkboxid').prop('checked', 'checked').prop('disabled', 'disabled');
}
else {
    $('#checkboxid').removeAttr('checked disabled');
}

Here’s a jsfiddle of it in action.

Updated: changed attr methods to prop as per @JohnStrickler’s recommendation.