Set a checkbox to unchecked if a Checkbox or Radio button isn't checked, when specifying by name and value

Set a checkbox to unchecked if a Checkbox or Radio button isn't checked, when specifying by name and value

I need to set a checkbox to be either checked or unchecked based on whether specific  Checkboxes or Radio button are selected.

I know how how to do this for checkboxes when I specify an id # for each element and use 

 if ($(this).attr('checked') , but I can't get it to uncheck when I specify the names and values of the checkboxes instead .


I also haven't been able to get it to uncheck when a radio button is unchecked, even when I specify an id # for each element and use if ($(this).attr('checked'). Ideally, I'd like to specify the names and values of the radio buttons instead of using ($(this).attr('checked'), but help with either method (or another one if there's a better way to go) would be appreciated.  I also included below a switch function which I'm using for Select elements, but which I've been successful at modifying to use with checkboxes or radio buttons.

I created a working fiddle of this at http://jsfiddle.net/Cfcq6/116/

Checkbox Code 2 - This code both Checks & Unchecks the element
  1. $('#complaint1').change(function() {
        if ($(this).attr('checked')) {
            $('input[name="modify_increase"]')[0].checked = true;
        }
        else {
            $('input[name="modify_increase"]')[0].checked = false;
        }
    });






Checkbox Code 2 - These Check but don't uncheck the element when unselected

  1. $('.complaint2').change(function() {
        if ($('input:checkbox[name=complaint2]:checked').val("Too_small")) {
            $('input[name="modify_increase"]')[0].checked = true;
        }
        else {
            $('input[name="modify_increase"]')[0].checked = false;
        }
    });






Radio Button - These check but don't uncheck the element when unselected

  1. $('#complaint3').change(function() {
        if ($(this).attr('checked')) {
            $('input[name="modify_increase"]')[0].checked = true;
        }
        else {
            $('input[name="modify_increase"]')[0].checked = false;
        }
    });






Switch function which works for Select Elements

  1.  $('.complaint1').change(function () {
            $('input[name="modify_increase"]').removeAttr("checked");
            $('input[name="modify_decrease"]').removeAttr("checked");
            switch($('[name=complaint1]').val()){
                case "Too_small":
                $('input[name="modify_increase"]')[0].checked = true;  
                break;
                case "Too_big":
                $('input[name="modify_decrease"]')[0].checked = true;  
                break;             
            }
      });