how to get checked and unchecked checkbox value in jquery

1//jQuery 1.6+ use
2$('.checkbox').prop('checked', true);  //false for uncheck
3//jQuery 1.5.x and below use
4$('.checkbox').attr('checked', true);  //false for uncheck

1if ($("#check_box_id").is(':checked')) {
2  alert("checked");
3}else{
4  alert("unchecked");
5}

1$("input:radio[name='NAME']:radio[value='VALUE']").attr("checked",true);
2$("input:radio[name='NAME']").removeAttr("checked");
3

1$('#submit').click(function(){
2		var redval = $('.red').val();
3		var grenval = $('.green').val();
4		$('.showCheckedValue').text(redval+'&'+grenval );
5	});