[lug] help! shell script

[legin]

hi friends,


        I was writing a shell script to uncompress all the files in the
directory.

        The shell script available below just uncompressed one file.

        The funny thing was that when i did a gzip using this shell
script it compressed

        all the files....Can any one help

------------------------------------------------------------
#!/bin/bash
for a in '*.tar.gz'
do
        tar zvxf $a
done
-------------------------------------------------------------

Thanks,
legin