Highlight text into textarea

[tranky]

Hola boys, i've a question for you!
It's possible to highlight some text inside a textarea? (not all text, but a portion!)
For example, i've this text inside a textarea.

[ B ] INSERISCI TESTO [ /B ]

i want to highlight only "INSERISCI TESTO".
It, must be an universal function, so i can use it also in other cases, for example when tag are [ SM ] and [ /SM].
I hope someone can help me, because through internet i find only code IE compatible e not FIREFOX compatible, and viceversa.
I'd like to have compatibility with both browser.

Thank you so much, for your help.
I'm waiting for you...

tranky

[Twey]

There is one in use on this very forum. Have a look at the source.