[Xastir] Dbfawk font_size

[Troy M. Campbell]

I'd like to display the label of a county (for example) depending on the
zoom level.

For example I'd like the county name to be display in font_size 1 at
zoom level 4096 but 
Font_size 3 at zoom levels less than 512.

Is there a way to do this?   I can't figure out the expression for it.

Thanks!

73 de Troy,  KC0MIC