Insert into caret position

[blufish]

okay, so I have a textbox where you enter text that you'll post to one of your contacts on my site.  when somebody clicks on an emoticon I want it to enter the syntax for the smilie (e.g. :-)) where the caret(blinking line thingy) is, I've been looking around and I can't seem to find much that explains how to do this, just a bunch of code.  I like to make my own codes, so if someone can tell me the javascript tags(is that what they're called?) that I can use to do this, that would be much appreciative.  I heard that there is a difference, like IE cannot do it the same way as all the others.  I want my site to be compatible with all browsers, so if you can tell me the differences how to seperate them and all that would be great.

 

Sorry if I sound whiny.