ติดปัญหาเรื่องการรับค่ามาเก็บไว้ในตัวแปรของjqueryครับ

<script>
var postdata;

		$('#search-btn').click(function(){
			postdata = $('#search').val();
			
				$.ajax({
				
				type: 'POST',
				url: 'http://localhost/master-cms/site/search',
				data: {search: postdata},//เปลี่ยน
				success: function(data1){
	
					var search_data = JSON.parse(data1);
	
					$.each(search_data, function(key, value){
					
						$('#sortTableExample tbody').append('<tr><td>'+value['stock_id']+'</td><td>'+value['stock_list']+'</td><td>'+value['stock_unit']+'</td><td>'+value['stock_qty']+'</td><td>'+value['stock_weight']+'</td><td>'+value['stock_price']+'</td><td>'+value['stock_catagorie']+'</td><td>'+value['stock_product_free']+'</td><td>'+value['stock_in_datetime']+'</td></tr>');
						$(".table").tablesorter({
							widthFixed: true,
							widgets: [ "zebra" ]
						});
	
					});
	
				}
	
			});
			
		});

		
</script>