open (IN, "<xxx.in");
while(<IN>)
{
    s/<volume>(.*)<\/volume>//;$vol=$1;
    s/<issue>(.*)<\/issue>//;$iss=$1;
    s/<year>(.*)<\/year>//;$yr=$1;
}
close(IN);
    print "Volume: $vol\n";
    print "Issue: $iss\n";
    print "Year: $yr\n";