$(function(){

	$('form#search-form .checkboxes-group').each(function(index) {
		if ($(this).children().length <= 3)
			return;
		var saChecked = $(this).find('input:checkbox:not(:checked)').length ? '' : ' checked="checked"';
		$(this).prepend('<div class="form-item select-all-checkboxes"><input type="checkbox" id="select-all-checkboxes-'+index+'"'+saChecked+' /> <label for="select-all-checkboxes-'+index+'">Select all</label></div>');
		$('.select-all-checkboxes input', this).click(function() {
			var check = this.checked;
			$(this).closest('.checkboxes-group').find('input:checkbox').each(function() {
				this.checked = check;
			});
		});
	});
});