源码如下：请大家帮我看看应该怎样实现？？
<?php
session_start();
include '../conn.php';
include 'function.php';
$uid=$_REQUEST['uid'];
$sql = "SELECT * FROM user where id = '".$uid."'";
$result = $conn->query($sql);
if ($result->num_rows <= 0) {
echo '请先注册或登录！';
exit;
}
?>
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>网购</title>
<link rel="stylesheet" type="text/css" href="../css/general.css">
<link rel="stylesheet" type="text/css" href="../css/index.css">
<script type="text/javascript" src="../js/jquery.js"></script>
</head>
<body>
<!-- 顶部开始 -->
<!-- 头部开始 -->
<?php include 'header.php'; ?>
<!-- 头部结束 -->
<!-- 主体开始 -->
<div class="center">
<p>请选择支付方式</p>
<br> <br> <br> <br>
<p >
<select class="shortselect" name="pay_method">
<?php
$sql = "SELECT * FROM pay ";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
?>
<option value="<?php echo $row['id']?>"><?php
echo $row['pay_method'];
?></option>
<hr>
<?php
}
}
?> </select></p><br>
<button class="button button2" onclick="window.location.href='paysuccess.php?uid=<?php echo $uid?>'">立即支付</button><br>
</div>
<!-- 页脚开始 -->
<div class="footer mt20">
<script type="text/javascript" src="../js/juicer.js"></script>
</body></html>
