0,1,2,NA Validation with FormCalc Script

Hi All,

I am attempting to create a validation for a text field with options of 0,1,2 and NA.  I originally started with

if (Within($,0,2) or $ eq "NA")

then

$=$

else

xfa.host.messageBox("Please enter a number 0-2 or NA")

$=null

endif

However this doesn't account for other text responses.  (If i were to enter "f" into this field with this code, for example, it would accept it.  I'm thinking the f registers as 0 in FormCalc, and so doesn't trip the validation script).

Anyone have some ideas for how to get around this?  Would very much appreciate any advice/guidance!

Thanks,

Matt