Save to a variable and then use #FOSI to check the value of the variable for content:
Works with either #NONE or #ANY
<att>
<specval attname="tpdr.tdv" attloc="#FOSI" attval="#NONE">
<charsubset>
<usetext source=""></usetext>
<reset resetlist="pagect" pageplus1ct"=">
</charsubset>
</att>
<att>
<specval attname="tpdr.tdv" attloc="#FOSI" attval="#ANY">
<charsubset>
<usetext source="\None\"></usetext>
<reset resetlist="pagect" pageplus1ct"=">
</charsubset>
</att>
-Andy
\ / Andy Esslinger LM Aero - Tech Order Data
_____-/\-_____ (817) 279-0442 1 Lockheed Blvd, Mail Zone 4285
\_\/_/ (817) 777 3047 Fort Worth, TX 76108