function sendLeaveRequest(studentId, startDate, endDate, reason) {

let xmlData = `

${studentId}

${startDate}

${endDate}

${reason}

`;

let xhr = new XMLHttpRequest();

xhr.open("POST", "http://example.com/leave", true);

xhr.setRequestHeader("Content-Type", "application/xml");

xhr.onreadystatechange = function() {

if (xhr.readyState === 4 && xhr.status === 200) {

console.log(xhr.responseText);

}

};

xhr.send(xmlData);

}

// 调用函数发送请假请求

sendLeaveRequest('123456', '2023-10-01', '2023-10-05', '家庭原因');