Acquiring reads that don't map to VIRGO

[ilkaybuysal]

Dear developers,

I was wondering if it's possible to acquire the reads that don't map to VIRGO?

I have been trying to use bowrie's --un argument out, but it doesn't work, unfortunately:
./runMapping.step1.sh -r ../non_human_SR1-050-150218_S9.fastq.gz -p non_human_SR1-050-150218_S9 bowtie --un non_VIRGO_non_human_SR1-050-150218_S9.fastq -d .../VIRGO-1.0/

Any suggestions?
Thanks a lot in advance.