Password protect zip files-Terminal help

Hi. running OS 10.7.4 on my MacBook Pro. I want to password protect a zip file (FPTGH.zip) to send to both PC and Mac users. I created the zip file using the finder. That worked like a champ. The file is on my desktop. I opened Terminal and entered zip -e, my zip file name.zip, entered the password (correctly) twice, and I repeatedly get the following message.

scm's MacBook-Pro:~ scm$ zip -e FPTGH.zip
Enter password:
Verify password:

zip error: Nothing to do! (FPTGH.zip)
scms-MacBook-Pro:~ scm$

Then I tried creating the zip from the original file, and I get the same message:

scm's-MacBook-Pro:~ scm$ zip -e FPTGH.txt
Enter password:
Verify password:

zip error: Nothing to do! (FPTGH.txt)
scms-MacBook-Pro:~ scmorgan$

WHAT am I doing wrong?

Stumped in Costa Rica. SC Morgan