微信公众号网页开发，获取 调用微信公众号接口后 的返回值，PHP

<?php
$myfile = fopen("fanhui.txt", "a+") or die("Unable to open file!");//打开一个文件，如果没有则创建，a+表示文件可读可写
$txt1 = "\r\n";//换行
$txt2 = "返回值信息";//返回值信息
$txt3 = date("Y/m/d G:i:s");//当前时间
$txt = $txt1.$txt2.$txt3;//拼接这三个字符串
fwrite($myfile, $txt);//将$txt写入文件
fclose($myfile);//关闭文件
?>

function fanhui($txt2){
	$myfile = fopen("fanhui.txt", "a+") or die("Unable to open file!");
	$txt1 = "\r\n";
	$txt3 = date("Y/m/d G:i:s");
	$txt = $txt1.$txt2.$txt3;
	fwrite($myfile, $txt);
	fclose($myfile);
}
fanhui($txt2);