在 PHP 中重定向到页面

我正在尝试根据其引用者重定向到页面.布局就像

I am trying to make a redirect to page based on its referrer. the layout is like

<?php
$URL_REF = $_SERVER['HTTP_REFERER'];
if($URL_REF == "url of my site") {
    header("Location: url of another site"); 
    exit();
}
else    {
    header("Location: my home page"); 
    exit();
}

?>

我收到错误:无法修改标头信息 - 标头已由发送.

我必须将我的 php.ini 修改为 output_buffering = On 但我不能这样做，因为我在 hostgator 中有一个共享主机帐户.谁能建议我现在有哪些选择?我可以通过更改代码来实现吗?如果是，那么有哪些变化?

I have to modify my php.ini to output_buffering = On but I can't do this as I have a shared hosting account in hostgator. can anyone suggest me what options now I have? can I do it by changing my code? If yes, than what changes?