BEGIN { 
 $ENV{DOCUMENT_ROOT}=~m/^([\w\-\/]+)$/i; 
 eval "use lib '$1/../lib';"; 
}

# this is unreliable:
#BEGIN {
# use lib do {
#   $ENV{DOCUMENT_ROOT}=~m/^([\w\-\/]+)$/i;
# } . '/../lib';
#}