Yes No Boolean conversion help

[gwarden]

I'm sure this is going to be a stupid question, but I'm still new to this seam stuff.  I'm trying to display yes/no instead of true false from a Boolean variable, but I need the Yes/No to draw from the active messages.properties file, so it can be multilingual.  I tried using the trinary operator

#{var?messages.yes:messages.no}

but that throws a parsing error. Any help?

[gwarden]

I should probably mention, this is for outputting to a pdf.