ติดปัญหาเรื่อง Check Box ไม่ได้ติ๊ก แต่ Update เข้าไปใน Database

<input type="checkbox" id ="TEST" class="TEST" value="Y" <?php if($num_row['TEST']=='Y') echo 'checked';?>>&nbsp;TEST PROGRAM<br>&nbsp;

$('.UPDATE').click(function()
{
		
			if ($('.ATT').val() == '')
			{
				swal("Remind","check ATT Empty","warning");
				return;
			}			
			swal
			({
			  title: "Are you sure?",
			  text: "Confirm Work_Eng",
			  type: "warning",
			  showCancelButton: true,
			  confirmButtonColor: "#356e35",
			  confirmButtonText: "Yes, Confirm Void!",
			  closeOnConfirm: false
			},

function()
			{
				$('.wm').waitMe({effect : 'bounce'});
				$.post("controller.php",
				{					
					checkfuction : 'WORKENG',												
					TEST : $('.TEST').val(),		
					DocRef : $('.DocRef').val()		
				   
				},
				
				function(rs)
				{
					$('.wm').waitMe("hide");
					if (rs.check == 'SaveOk')
						{
						location.replace("<?php echo $total ?>");
					}
					else if(rs.check == 'same')
					{
						swal("Error","TYPE Duplicate","error");
					}
					else
					{
						swal("Error","Please Check Data Or Contact EDP!","error");
					}
				},'JSON')
			});

})

function WORKENG($param)

{

$sql = "UPDATE TEST_PROGRAM	
SET REFDOC = '".$param['DocRef']."'";
 
if($param['TEST']!=NULL)$sql.=", TEST='".$param['TEST']."'";else $sql.=", TEST=NULL";    
$sql.= "WHERE DOCNO = '".$param['DOCNO']."'";

ConnectManage($sql);

$data['check'] = 'SaveOk';

echo json_encode($data);
	
}