proid 是用来干嘛的？urldecode($_GET['proid'])报错
$rs2=mysqli_query($link,"select * from lend where book_id='".$rows['id']."' and user_id='".$_SESSION['id']."'");
$_SESSION['id']报错，要怎么改？
求解
将$_SESSION数组打印出来,还有会话是否开启?
将$_SESSION数组打印出来,还有会话是否开启?