Autocomplete ที่จำกัดจำนวน record ในการแสดงผลทีละ 20 รายการต้องเพิ่ม code ตรงส่วนไหนคะ แนะนำหน่อยค่ะ

var availabletxtMajors_desc=[<?
		    $sqlMajors_desc= " SELECT DESCRIPTION50||'/'||PROGRAM_NAME_ENG NAME FROM APPM_MAJOR ORDER BY DESCRIPTION50 ASC ";  
		   $rsMajors_desc = &$db->Execute($sqlMajors_desc);
		    while ($dataMajors_desc= $rsMajors_desc->FetchRow()) { 
				echo "\"".$dataMajors_desc['NAME']."\",";
				} ?>
				];
		$( "#txtMajors_desc" ).autocomplete({
			minLength: 0, 
			source: availabletxtMajors_desc, 
			open:function(){ 
				var valInput=$(this).val();
				if(valInput!=""){
					$(".ui-menu-item a").each(function(){ 
						var matcher = new RegExp("("+valInput+")", "ig" ); 
						var s=$(this).text();
						var newText=s.replace(matcher, "<b>$1</b>");	
						$(this).html(newText); 
					});	
				}
			}
		});
	
		$( "<button type='button'>&nbsp;</button>" )
			.attr( "tabIndex", -1 ) 
			.attr( "title", "Show All" )
			.addClass("myselectword")
			.insertAfter("#txtMajors_desc") 
			.button({
				icons: {
					primary: "ui-icon-triangle-1-s"
				},
				text: false
			})
			.removeClass( "ui-corner-all" )
			.addClass( "ui-corner-right ui-button-icon" )
			.click(function() { 
				if ($( "#txtMajors_desc" ).autocomplete( "widget" ).is( ":visible" ) ) {
					$( "#txtMajors_desc" ).autocomplete( "close" ); 
					return;
				}
				$( "#txtMajors_desc" ).autocomplete( "search", "" );
				$( "#txtMajors_desc" ).focus();
		});							
    });