Javascript to make a html on/ off switch

OK. im making a news updating control panel.

heres what im looking for.

i have a text box for your news update.

is there anyway to have it, so that when you hit the return button, it inserts a <br> tag in the box?

if any of you have a xanga out there, you know what im talking about.

when you hit enter, you see that there has been a return, but there is no <br> tag visable. then when you hit “go” the “invisable return” is then turned into a <br> or something, and your output on the update is a return.

if you dont get what im asking, tell me, and ill elaborate more.