Its generally better to avoid inline style (the style attribute) in favour of an external style sheet. This makes things much easier to maintain in the long run.

Its also a very bad idea to use the pt unit since:

• Most browsers don't know the DPI of the screen, so can't render pts correctly
• Internet Explorer makes it very difficult for the user to override point units, which is a pain if you can't read text as small as the author chooses
• It pays no attention to the user's preferences for font size

Generally speaking, percentages are the best unit for font sizing.