ใช้ jquery เช็คค่าไม่ให้ซ้ำทำยังไงครับ ใครรู้วิธีช่วยบอกหน่อยครับ

<script type="text/javascript">
$(document).ready(function(){
	$( "#form1" ).validate({
		rules: {
			m_no: {
				required: true,
				remote: {
					type: "post",
					async: false,
					url: "check_no_meeting_duplicate.php",
					data: {
						m_year: function() {
							return $( "#m_year" ).val();
						},
						m_no: function() {
							return $( "#m_no" ).val();
						}
					},
					dataFilter: function(data) {
						var json = JSON.parse(data);
						if (json.success) {
							return '"true"';
						} else {
							return "\"" + json.msg + "\"";
						}
					}
				}
			}
		},
		messages: {
			m_no: {
				required: "*Please enter NO. of meeting. ",
				remote:"*This No. is already.",
				digits:(" *Please enter a valid No. Number."),
			}
		}
	});
});
</script>

<?php

	require_once("connect.php");
	$m_year = $_GET["m_year"];
	$m_no = $_GET["m_no"];
	
	$strSQL ="SELECT * FROM meeting WHERE meet_no = '".$m_no."' AND meet_year ='".$m_year."'";
	$objQuery = mysqli_query($con,$strSQL);


	if(mysqli_num_rows($objQuery)>0){   
        echo json_encode(array('success'=>false,'msg'=>'Not duplicate!'));
	} 
	else {
		echo json_encode(array('success'=>true,'msg'=>'Duplicate data!'));
	}

?>

if(mysqli_num_rows($objQuery)>0){   
        echo json_encode(array('success'=>false,'msg'=>'Not duplicate!'));
}else {
	echo json_encode(array('success'=>true,'msg'=>'Duplicate data!'));
}

	data: {
		m_year: function() {
			return $( "#m_year" ).val();
		},
		m_no: function() {
			return $( "#m_no" ).val();
		}
	},

data: { m_year: $( "#m_year" ).val(), m_no: $( "#m_no" ).val() },

<script src="jquery/lib/jquery-1.8.3.js"></script>
<script src="jquery/lib/jquery.validate.js"></script>
<script src="jquery/lib/additional-methods.js"></script>
<script type="text/javascript">
$(document).ready(function(){
	$("#form1").validate({
			rules: {
				m_year:"required",			
			        m_no: {
                                     required: true,
				     digits :true,
                                     remote: {
                                           type: "post",
                                           async: false,
                                           url: "check_no_meeting_duplicate.php",
                                            data: {
						m_year: function() {
							return $( "#m_year" ).val();
						},
						m_no: function() {
							return $( "#m_no" ).val();
						}
					},

				},
			
			messages: {
				m_no: {
					required: "*Please enter NO. of meeting. ",
					remote:"*This No. is already.",
					digits:(" *Please enter a valid No. Number."),
					
				},
			},
	});
	
});
<form class="form1" id="form1" method="post" >
  <div>
     <select style="width:200px; height:30px;" name="m_year" id="m_year">
            <option value=""><-- Please Select Year --></option>
            <option value="2015">2015</option>
            <option value="2016">2016</option>
            <option value="2017">2017</option>
            <option value="2018">2018</option>
            <option value="2019">2019</option>
            <option value="2020">2020</option>
      </select>
  </div>
                         
  <br><div>
       <input type="text" name="m_no" id="m_no" style="width:50px; height:25px;" />
  </div></br>
   <input type="submit" id="submits" style="visibility: hidden;"/>
</form>
</script>

<?php

	require_once("connect.php");
	$m_year = $_GET["m_year"];
	$m_no = $_GET["m_no"];
	
	$strSQL ="SELECT * FROM meeting WHERE meet_no = '".$m_no."' AND meet_year ='".$m_year."'";
	$objQuery = mysqli_query($con,$strSQL);

	
	if(mysqli_num_rows($objQuery)==0){ 
	// หาไม่เจอ ไม่พบรายการซ้ำ
	echo json_encode(array('success'=>true,'msg'=>'Not duplicate!'));
	}else {
	// หาเจอ ซ้ำกัน
	echo json_encode(array('success'=>false,'msg'=>'Duplicate data!'));
	}

?>