Protect special chars

ok i wrote a plugin that allows me to input a text and the text then is added to the current curse position. everythink ok so far. my problem is that i wrape that text in a pre tag and the text i paste into the textarea in my dialog is source code. my problem is that if is save it, characters like > are shown as > and so on.
i want to disable that conversion.

ps. i use geshi to highlight the code

thank you for helping.