Need help with scripting

[Kenneth Macdonald Karlsen <ken@fiona-victor.com>]

Hi all.
Im sorting out my 2000+ mp3 files.
Some of them i want to convert to wav files of various reasons.
Its a rather boring job to do that manualy so i thought i would write a
script. Im VERY inexperienced in this so help is needed.
Ive got this far:

ken@pingu:~/brenning/test$ cat skript 
#!/bin/bash
clear
echo "type name of file that shall go from  mp3 to wav"
echo "ending of file is mp3.wav not solved yet"
read filename
mkdir wavfiles
mpg321 --w  $filename.wav $filename
#rm -rf $filename
mv $filename.wav wavfiles

Problems:
1. The script cant take wildcard input and sort the files out with the
same names and different extension.
1. It only takes one file at a time.
2. I cant get shell access to type filename, eg for using tab (minor
problem)

Any help appreciated.
Kenneth