Can any body help me on how to check whether a file contains a required extension or not.

pseudo is:

if (filename contains .jpg || filename contains .gif)
--- do some thing
end if

Example file names:
test1.grm.gtrx.drx.jpg
test.de.mi.jpg
test2.ds.gif
test3.gif

thanks in advance

Somebody suggested in one of the messages and with that, could make it like this:

suffix=${filename##*.}

if [ $suffix = "jpg" || $suffix = "gif" ]; then
-- do something
fi

See wildcards with if statement?