Bash Shell Scripting

I need a shell script to change the name of files/directories with spaces in the name to be dashes instead of spaces. So, if a file/directory were named "A B", the new name would be A-B.

The script will work on a directory specified on the command line and replace the spaces in the names for all files/directories underneath that directory.

The options to the script are as follows:
-f the -f to only rename files
-d the -d to only rename directories
Both -d and and -f may be specified.


Example:
$ls
C D/

./C D
./C D/E F
./C D/E F/G H
./C D/E F/G H/J K
./C D/E F/G H/J K/a b
./C D/E F/G H/a b
./C D/E F/a b
./C D/a b

After script runs:

C-D
C-D/E-F
C-D/E-F/G-H
C-D/E-F/G-H/a-b
C-D/E-F/G-H/J----K
C-D/E-F/G-H/J----K/a-b
C-D/E-F/a-b
C-D/a-b

Some of the code will be provide and the final script must implement the code that will be provided.