set checked a checkbox code example
Example: jquery checkbox set checked
//For jQuery 1.6 and above
$('#myCheckBoxID').prop('checked', true);
//For jQuery Before 1.6
$('#myCheckBoxID').attr('checked','checked');
//For jQuery 1.6 and above
$('#myCheckBoxID').prop('checked', true);
//For jQuery Before 1.6
$('#myCheckBoxID').attr('checked','checked');