Selecting a textarea range based on surrounding text boundary

[gf]

I have text in a textarea that looks like this:

++++++++++++
This is line 1
This is line 2
++++++++++++
This is more text 1
This is more text 2
This is more text 3
++++++++++++
etc.
etc.
++++++++++++

I need to be able to click anywhere within the text bordered by ++++
and have all the text selected. A cross browser routine would be the
best (obviously), but if not possible, next best would be the latest
browsers, and if that's not possible, then IE only.

Thanks!