if / else path not as expected on return value of last command

       sh $CPB_BIN/nm187_sort.sh $CPB_TRANS/$SORT_FILE_ORIGINAL $CPB_TRANS/$OUTPUT_FILE

       if [ $? == -1 ]
       then
          print "Nonmon sort command failed: $!\n"
                      exit 1
       else
          print "Nonmon sort command exited with value $?\n"

For some reason if the sort script fails, its still taking the else part. What am i missing?