Perl issue

[Sayed, Irfan \(Irfan\)]

Hi,
 
I am executing following perl script 
 
# perl script to change the hostname of every replica / VOB
 
use strict;
 
my $CT = "ct";
 
my @vob_list = `$CT lsvob -s`;
 
print "Following are the VOBs / Replicas whose hostname needs to be
change \n";
 
print @vob_list;
 
foreach my $a (@vob_list)
 {
       print $a;    
      `$CT lsreplica -fmt %[master]p\n -invob $a`; 
 
 }

If i print the value of $a then the output is fine but the moment i
execute this command
 
     `$CT lsreplica -fmt %[master]p\n -invob $a`; 
 
it is giving me following error. 
 
 cleartool: Error: Unable to determine VOB for pathname ".".
 
The values in the $a are all VOB tags which are as follows
 
\openssl_openssl
\openssl_openssl_rel
\gatne_tut_input_vob
\gatne_tut_tools_vob
\bt_rel
\geneva
\UMAdminVob
\UMDistrib
\UMShared
\UMTools
\avb
\avb_rel
\sun_j2sdk_142_03
\apache_tomcat_5028
\cs_security_certMgmt
\apache_tomcat
\apache_tomcat_rel
\codehaus_activemq
\codehaus_activemq_re
\apache_axis_rel
\cs_rhel4
\cs_common_external
\raja_test
\nas_test1
\cs_snmp_toolkit
\cs_alarming_cli
 
Please let me know what i am doing wrong
 
Regards
Irfan.