Some XMl (FontString) trouble

[Bait the Bard]

I've been working on a little mod of my own for the past few weeks, and I'm having a bit of trouble displaying text to the UI. The text is there, but is currently very small in font-size. I've tried various sizes in the FontString attribute, but they don;t seem to change anything.

I was wondering if you guys could tell me what to do, or point me to relevent threads/articles.

The relevent code is as follows:
<MessageFrame name="AddOn_Frame" insertMode="TOP" parent="UIParent" frameStrata="HIGH" toplevel="true">

<Scripts>
<OnLoad>
AddOn_OnLoad();
</OnLoad>
<OnEvent>
AddOn_OnEvent();
</OnEvent>
</Scripts>

<FontString inherits="GameFontNormal" justifyH="CENTER">
<FontHeight>
<RelValue val=".35"/>
</FontHeight>
</FontString>

<Size>
<AbsDimension x="400" y="50"/>
</Size>


</MessageFrame>


Thanks for your time.
- Bait