php问题：Warning:Cannot modify header information - headers already sent by (output started at

php问题：Warning:Cannot modify header information - headers already sent by (output started at
php问题：Warning:Cannot modify header information - headers already sent by (output started at

php问题：Warning:Cannot modify header information - headers already sent by (output started at
php header ()之前不能输出内容,建议用JS跳转,把所有header()换成
echo 'location.href="error.php"';

建议用JS跳转

既然都写了history.back(); 下面怎么还跳转到error.php 页面？ 建议把header（）替换掉history

header ("location: error.php");前面不能有输出内容。