读取4个数据库的值

<script>
	// 在这里编写 JavaScript 代码
	// 使用 AJAX 技术从服务器获取数据

	// 从数据库1读取数据
	var xmlhttp1 = new XMLHttpRequest();
	xmlhttp1.onreadystatechange = function() {
		if (this.readyState == 4 && this.status == 200) {
			document.getElementById('db1').innerHTML = this.responseText;
		}
	};
	xmlhttp1.open("GET", "database1.php", true);
	xmlhttp1.send();

	// 从数据库2读取数据
	var xmlhttp2 = new XMLHttpRequest();
	xmlhttp2.onreadystatechange = function() {
		if (this.readyState == 4 && this.status == 200) {
			document.getElementById('db2').innerHTML = this.responseText;
		}
	};
	xmlhttp2.open("GET", "database2.php", true);
	xmlhttp2.send();

	// 从数据库3读取数据
	var xmlhttp3 = new XMLHttpRequest();
	xmlhttp3.onreadystatechange = function() {
		if (this.readyState == 4 && this.status == 200) {
			document.getElementById('db3').innerHTML = this.responseText;
		}
	};
	xmlhttp3.open("GET", "database3.php", true);
	xmlhttp3.send();

	// 从数据库4读取数据
	var xmlhttp4 = new XMLHttpRequest();
	xmlhttp4.onreadystatechange = function() {
		if (this.readyState == 4 && this.status == 200) {
			document.getElementById('db4').innerHTML = this.responseText;
		}
	};
	xmlhttp4.open("GET", "database4.php", true);
	xmlhttp4.send();
</script>