Warning: preg_replace(): Unknown modifier ‘p’

$url_query=preg_replace(“{^|&}page=$page”,””,$url_query);
这个应该怎么修改才不报错呢?

Warning: preg_replace() [function.preg-replace]: Unknown modifier ‘p’
错误解决办法:
加上定界符 $url_query=preg_replace(“/{^|&}page=$page/”,””,$url_query);