regular expression

[John Smith]

how to do in order to retrieve the content between '<AAA>' and </AAA>

let's say the text is :

<AAA>a</<AAA><BBB><AAA>ab</AAA></BBB> ...

???

 

[Matthew Lock]

how to do in order to retrieve the content between '<AAA>' and </AAA>

let's say the text is :

<AAA>a</<AAA><BBB><AAA>ab</AAA></BBB> ...

???

Do you really mean: "</<AAA>", or was that a typo? Anyway it looks like
you are trying to parse HTML or XML. I would recommend using the DOM
functions in your browser from Javascript instead.