UNIX for Dummies Questions & Answers

This is my task:

For Example,
$ valid_name "John Smith"
John Smith is valid
=========
$ valid_name "John smith"
John smith is not valid
=========
$ valid_name "John"
John is not valid
==========
$ valid_name "jOhn Smith"
jOhn Smith is not valid
===========
$ valid_name "John sMith"
John sMith is not valid






This is what I have so far:

Code:

if [ $# -ne 1 ]
then echo usage: enter 1 agrument
exit 1
fi
if [ "$1" = $( ]
then echo $1 is valid
else echo $1 is not valid
fi

I need to use grep or sed somehow right? I cannot figure this out for the life of me.

Please help.

---------- Post updated at 10:17 PM ---------- Previous update was at 08:33 PM ----------

Now I have this but I need help with the pattern to make all the examples work:

Code:

if [ $# -ne 1 ]
then echo usage: enter 1 agrument
exit 1
fi
if [ "$1" = "$(echo $1 | grep '[A-Z]*\ [A-Z]*')" ]
then echo $1 is valid
else echo $1 is not valid

Is this a homework?