您必须准确地回显字符串'true'，如果希望允许它通过，则无需执行其他操作.其他任何内容('false'，null，undefined或任何字符串)都将被解释为无效，并且如果存在字符串，则将显示该字符串.

You have to echo exactly the string 'true' and nothing else if you want it to be allowed through. Anything else ('false',null,undefined, or any string) will be interpreted as invalid and if there is a string, that string will be displayed.

因此，请仔细检查您的PHP脚本目前仅打印出'true'或'false'.如您所显示的脚本将打印电子邮件，后跟'true'或'false'.始终将其解释为false.

So check carefully that your php script is printing out only 'true' or 'false' for now. The script as you've shown it prints the email followed by 'true' or 'false'. This will always be interpreted as false.

阅读远程方法的文档:

该响应被评估为JSON，并且必须为true才有效 元素，可以是任何false，undefined或null(表示无效) 元素，使用默认消息；或字符串，例如那个名字是 已经采取，请尝试改为使用peter123"作为错误消息显示.

The response is evaluated as JSON and must be true for valid elements, and can be any false, undefined or null for invalid elements, using the default message; or a string, eg. "That name is already taken, try peter123 instead" to display as the error message.

使用Firebug或Chrome Inspector验证您的响应正确无误.

Use Firebug or Chrome Inspector to verify that your response is correct.