YYCOllie, I see you're trying to add codes to bold and italic. You've got the codes (b and i) right, but the delimiters are [square brackets] not <angle brackets>.
Some other useful UBB codes are
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">[ quote ]</font>
and
and there are others, including some of the fancy smiley and frowney faces.
andrew