想要透過select表單的值來控制chart的數據
不過卡在兩個地方
1.加上 <script src="Chart.js"
之後，原先能使用的onchange函式就無法使用了
顯示Uncaught ReferenceError: monthsearch is not defined
at HTMLSelectElement.onchange，可是不加上這行就無法使用chart元件了

2.原本在從php的數據內已經抓到了想要的數值
月份在資料表內有1~12還有相對應的total數據，我已經把這兩個切成兩個陣列
NewArray[0]和NewArray[1]，各分為1~4、5~8、9~12以及相對應的total值，可是不曉得要如何放到labels和data裡面，想問有什麼方法?

程式碼:
index.php
`

    success: function(message){
        
		var a=message;
		var NewArray = new Array();

　 var NewArray = a.split("");
console.log(NewArray[0],NewArray[1]);
document.getElementById("monthshow2").innerHTML=NewArray[0];
document.getElementById("monthshow3").innerHTML=NewArray[1];
},

    error: function(jqXHR, textStatus, errorThrown){ 
        document.getElementById("monthshow").innerHTML=errorThrown; 
    }
});

}

var ctx = document.getElementById('myChart');
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['一月', '二月', '三月','四月 '],
datasets: [{
type: 'bar',
label: '銷售業績(百萬)',
data: ['77', '99', '72','80']

}, {
  type: 'line',
  label: '新開發客戶',
  data: ['25', '99', '30','90']
}]

}
});

};

monthchaeck.php
`<?php
header("Content-Type: text/html; charset=utf-8");
$start=$_POST['month'];
$end=$start+3;

$db_host = "localhost";
$db_username = "root";
$db_password = "a123456s";
//連線伺服器
$month=array();
$total=array();
$db_link = @mysqli_connect($db_host, $db_username, $db_password);
if (!$db_link) die("資料連結失敗！");
//設定字元集與編碼
mysqli_query($db_link, "SET NAMES utf8");
$seldb = @mysqli_select_db($db_link, "test");
if (!$seldb) die("資料庫選擇失敗！");
$sql_query = "SELECT month FROM month where month between $start and $end";
$result = mysqli_query($db_link, $sql_query);
while($row_result=mysqli_fetch_assoc($result)){
foreach($row_result as $value){
$month[]=$value;
}
}
foreach($month as $value){
echo $value." ";
}
echo "";
$sql_query = "SELECT total FROM month where month between $start and $end";
$result = mysqli_query($db_link, $sql_query);
while($row_result=mysqli_fetch_assoc($result)){
foreach($row_result as $value){
$total[]=$value;
}
}

		foreach($total as $value){
		echo $value." ";		
	}

?>`