FTP permissions in dreamweaver

I’ve read the tutorial in this site about how to create a guestbook with flash, xml and php. I uploaded the tutorial files in my server but looks like the php script isn’t able to access the xml file. The tutorial talks about changing the CHMOD permissions to 777.¿How do you do that in dreamweaver?

go to window/results/ftplog and type in the command bar

site chmod 755 /path/to/your/file

I haven’t tried it. I just typed ‘dreamweaver chmod’ into google.

it worked
I typed
site chmod 777 /(…)/guestbook.xml