On-Screen messages

[Chilton]

EDIT: Ok, im slightly tired so excuse me for being slightly informal

Ok;
Basically, im trying to make a message appear on-screen when i enter an area script.
I imagine

GiveHint(string& asName, string& asMessageCat, string& asMessageEntry, float afTimeShown);
Or SetMessage, in which case, how what are the categories?

Or one of the 'Hint' Scripts would be the one to use, but the main problem is that im fairly new to XML Scripting, and thusly have no idea what the the bold parts mean - So, i suppose someone couldnt fill in a dud script which would display a message on screen upon entering an area, with insertmsghere or somesuch were a message would go?

Any aid is much appreciated