I have a textarea that I want to disable when some condition is met, else it will be enabled.
<textarea name='example'>I want to disable this</textarea>
I tried this method, but it's not working:
$('#example').attr('disabled', true);
Use attribute-value selector
To disable a textarea
$('textarea[name="example"]').prop('disabled', true); // disable
To enable
$('textarea[name="example"]').prop('disabled', false); // enable
Demo
$('#myButton').on('click', function() {
  var currentState = $(this).text();
  $('textarea[name="example"]').prop('disabled', currentState === 'Disable');
  $(this).text(currentState === 'Enable' ? 'Disable' : 'Enable');
});button {
  display: block;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.0/jquery.min.js"></script>
<textarea name='example' disabled>I want to diable this</textarea>
<button id="myButton">Enable</button>Use $("#textbox1").attr("disabled", "disabled"); to disable your text box.
Demo
HTML
<span id="radiobutt">
  <input type="radio" name="rad1" value="1" />
  <input type="radio" name="rad1" value="2" />
  <input type="radio" name="rad1" value="3" />
</span>
<div>
  <input type="text" id="textbox1" />
  <input type="checkbox" id="checkbox1" />
</div>
Javascript
$("#radiobutt input[type=radio]").each(function(i){
  $(this).click(function () {
    if(i==2) { //3rd radiobutton
       $("#textbox1").attr("disabled", "disabled"); 
       $("#checkbox1").attr("disabled", "disabled"); 
    }
    else {
       $("#textbox1").removeAttr("disabled"); 
       $("#checkbox1").removeAttr("disabled"); 
    }
  });
});
 
    
    you should use the .prop() function with attribute-value selector
$('textarea[name="example"]').prop('disabled', true);
//$('textarea[name="example"]').prop('disabled', false);
Note: For jQuery 1.6+
or
$('textarea[name="example"]').attr("disabled","disabled");
