i tick checkbox but it is unchecked code example

Example 1: jquery set checkbox checked unchecked

//jQuery 1.6+ use
$('.checkbox').prop('checked', true);  //false for uncheck
//jQuery 1.5.x and below use
$('.checkbox').attr('checked', true);  //false for uncheck

Example 2: jquery checkbox unchecked

$("input:radio[name='NAME']:radio[value='VALUE']").attr("checked",true);
$("input:radio[name='NAME']").removeAttr("checked");