but it wont work. Help

Well what code are you using? The easiest way would be with the font tag but if you are more advanced you could use CSS...font tag example...

Hello my name is <font face="arial">David</font>

just adding the CSS version, in case you want to use that too :)

Helly my name is <span style="font-family: arial, verdana, serif">David</span>

Well there you have it! I would use the HTML if I were you - see the majority of my other posts telling people that not everyone has CSS. :P