[izpack-users] variable value in pack file src ?

[E.othman]

is it possible if i defined a variable "JBOSS_DIR"  to use it in  pack 
file src ?
i tried this:

<pack name="jboss" required="no">
<description>JBOSS Installer.</description>
<file src="${JBOSS_DIR}" targetdir="$INSTALL_PATH"/>            
</pack>
but i got a compilation error !
how can do the above task correctly ?

thanks