browser doesn’t see my install file

thanks in advance, anyone:
On a mac using FF, I installed on my server into a folder marked “wordpress” at the root level. I dialed up the install page, and got the ‘Welcome’ window, and the prompt for PW and email address. but after clilcking ‘install’ and passing through, I didn’t get the Success window nor the temp PW……..and I can’t seem to go back to the install window…..
Using an FTP client, I can see the file is there.

most grateful for any help….!

files are here:
http://www.tbfa.com/wordpress/ad-min/install.php